Concentration Profile In Membrane Phase And Ass Transfer Characteristics In Bulk Liqid Embranes

Liquid membrane processes combine extraction and stripping into onesingle stage by membrane permeation. Compare unit operation of solventextraction, the carrier or the extractant acts as a shuttle to transport the soluteand can not be saturated by feed. However, there have little studies aboutsolute concentration profile of membrane phase in liquid membrane process.In addition, the solute accumulation in the beginning of liquid membraneprocess is always closely connected to stripping rate, which further have agreater impact on the whole separation process. So quantitatively study to theconcentration profile in membrane phase could make us more clear to themass transfer characterization of LM processes, within some improvisesignificant to practical model building of LM progress.In this paper, a system which been extensively researched, phenol/TBP n nephtane/NaOH was used as the model system. First, the extractionand stripping chemical reaction equilibrium constant Keqare obtained bycalculation of the regression of solvent extraction equilibrium experimentsresults. Then the distribution coefficient under different condition could becalculated by the Keq. And the effect of of loading phenol concentration onextraction rate is studied by extraction kenetics experiment.The concentration profiles in the different phase of LM is studied bydesigning a novel bulk liquid membrane (BLM) configuration, andhydrodynamic conditions of feed, chemical factors are also been investigatedon the basis of solution accumulation of LM phase. The effect of agitateintensity in membrane phase on solute accumulation is quantitatively studied through the dimensionless mass transfer correlation and diffusion model.The results demonstrated that the equilibrated membrane concentration isnot related to the inventory of membrane phase and the time to reach thesteady state decrease with decreasing the volume of membrane phase. Theinterface areas, chemical reaction factors, hydrodynamic conditions are alsorelevant to the equilibrated membrane concentration or the equilibrated time.These conclusions could be expanded to other similar states of liquidmembrane processes.