Separation of Styrene-Ethyl Benzene Mixture Through Hydrotropy

The field of separation using hydrotropy has been studied. Solvent extraction and extractive distillation with aqueous solutions of hydrotropes are the novel separation techniques suitable for separation of close boiling mixtures. The present work is concerned with the separation of styrene-ethyl benzene mixture using hydrotropic solutions of urea, nicotinamide and sodium benzoate. The influence of a wide range of hydrotrope concentrations (0 to 3.0 mol/L) and different system temperatures (303 to 333 K) on the separation of styrene and ethyl benzene mixture was studied. The percentage extraction of styrene from the styrene-ethyl benzene mixture increases with an increase in hydrotrope concentration and also with system temperature. A Minimum Hydrotrope Concentration (MHC) was found essential to initiate significant extraction of styrene from the styrene-ethyl benzene mixture. The maximum enhancement factor, which is the ratio of the value in the presence and absence of a hydrotrope was determined. The Setschenow constant, Ks, a measure of the effectiveness of a hydrotrope, was determined for each case.