SEPARATION OF HYDROCARBON BY O/W/O EMULSION LIQUID MEMBRANE WITH CONTINUOUS COUNTERCURRENT PACKED-COLUMN

In the first stage, an attempt was made to select the type of packing for an emulsion liquid membrane process by permeation experiments with an aromatics non-aromatics binary mixture as an inner oil phase in the emulsion. Mechanical entrainment of a portion of the outer oil phase into the membrane phase, which frequently results in unfavorable phase inversion, was not detected at all with any packing. A packing whose surface is wetted with the emulsion (the dispersed phase) was recommended for this separation technique in order to avoid membrane breakage and to improve separation selectivity, whereas a packing which is not wetted with the dispersed phase is used in an ordinary liquid-liquid operation. Secondly, with the emulsion-wettable packing, further experiments were conducted under various conditions and the mass transfer coefficient was correlated. Major resistance to overall permeation resided in the emulsion. Independently of the feed system and the composition, the dimensionless mass transfer coefficient in the emulsion could be correlated by a simple dimensionless equation with two dimensionless numbers. The mass transfer coefficient for the permeation in the opposite direction (the inward permeation) could also be represented roughly by this equation.