REMOVAL OF ORGANIC VAPORS BY MEMBRANES

Even on consistent use of production-oriented environmental protection measures it still proves impossible to avoid the formation of solvent -containing gaseous effluents in many production processes. Thus the r eduction of emissions by purification of solvent-containing process an d exhaust gas streams is still a highly topical matter. Thermal, catal ytic, or biological oxidation processes leading to destruction of the organic solvents should only be used when solvent recovery is impossib le. Preference should always be given to those processes which protect resources by permitting recovery of solvent. Substantial advances in the area of membrane technology during the past ten years mean that ga s permeation now constitutes an interesting alternative to conventiona l processes. Combination of a membrane separation stage with direct or indirect condensation gives a hybrid process permitting gentle and co ntamination-free recovery of organic components, This article briefly summarises the fundamentals of permeation of gas/vapour mixtures throu gh polymer membranes.