INDUSTRIAL APPLICATION OF MEMBRANE SEPARATION PROCESSES

During the past two decades membrane separation processes have been developed and optimized for even large scale industrial applications. The most important of these processes include: (i) microfiltration and ultrafiltration for purification of aqueous streams, concentration and recovery of valuable products; (ii) reverse osmosis for the production of demineralized or potable water, (iii) electrodialysis for the concentration or removal of dissolved ions; (iv) gas separation for splitting gas streams, removal or recovery of specific gases; (v) pervaporation for separation and concentration of liquid mixtures, especially of aqueous-organic azeotropes. Whereas the first three of these processes are well established and have reached a high degree of maturity, the last two ones are still in developing stage, although development is fairly fast. Both processes, gas separation and pervaporation are very closely related with respect to their physicochemical fundamentals. In this paper principles of the separation processes are outlined. Examples of membrane performance and applications, with the emphasis on Pervaporation processes are presented.