Separation Of Organic Solvent Mixtures Sing SRNF

SRNF is a rising membrane process, which can replace traditionalseparation systems in the chemical, pharmaceutical and biotechnologyindustry where solvents are used in production. For the development of newapplications, it is necessary to find out the parameters determining the processperformance.This paper takes the SRNF process into solvent mixtures tries to find out thekey factors which have significant influence on the separation of solventmixtures. First, solvent fluxes were measured at some temperature in dead-endmode for four membranes, i.e. MPF-44, MPF-50, STARMEM240andDuraMem150. Viscosity, surface tension, dielectric constant and solubilityparameter of solvent seem to be significant on the flux of solvent. Thesefactors were taken into the mixed system; nine kinds of binary mixtures weredesigned. The separating ability of several solvent resistance membranes inthe different systems was studied. Among them, DuraMem150membrane inthe binary mixtures of ethanol and hexane shows a separation factor close to6,has clearly confirmed the theory feasibility of separation in solvent mixtures using SRNF process. For the ethanol and hexane system, we research thepreference of ethanol getting through the membrane, discover the solutiondiffusion mechanism can explain the phenomenon that single componentpreferentially get through the membrane. The solubility parameters can beused to determine the interaction force of the three. We firstly propose aqualitative inequality for explaining the reason why singlecomponent can preferentially get through the membrane.The micro-structural properties of the DurMem150membrane wereinvestigated by using SEM, XPS and FTIR-ATR.We find the DurMem150membrane is a typical dense membrane. Mixed solvent can be separatedbeacuse the differences in solubility on the membrane surface and thediffusion velocity in the membrane. According to the inequality, we selectedtwo kinds of binary solvent system and study the separation using MPF44DuraMem150. The rationality of the inequality is confirmed. The mixedsolvent separation on SRNF is still in preliminary research, and need morereaserch for the further application of SRNF in the solvent separation.