Abstract
A binary mixture of hydrocarbons was separated by the batchwise liquid membrane permeation technique. Benzene-n-hexane was selected as a hydrocarbon feed mixture together with iso-octane as a solvent and an aqueous solution of saponin and glycerine as the membrane phase. With the assumption that the total rate of mass transfer for the permeable component consists of the rate of permeation, the rate of membrane breakage and the rate of mechanical entrainment, the contributions of these individual rates on the total rate were calculated. Membrane breakage had no influence practically on the more permeable benzene, but some detrimental effect on the less permeable hexane, where it caused a definite drop in membrane selectivity. After a relatively long period of contact, when the benzene content in the extract phase became higher, entrainment affected seriously the rate of benzene transfer. The overall permeabilities were 3-7 g/ (m2·min) for benzene and 0.2-0.5 g/ (m2·min) for hexane. The maximum membrane selectivity was about 45.
