Effective separation of petro products through hydrotropy

Abstract

This paper presents a comprehensive study on the effect of hydrotropes such as sodium salicylate, sodium benzoate, and nicotinamide on the separation of a near boiling mixture, o-/p-xylene. 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 o-/p-xylene were studied. All hydrotropes used in this work showed an enhancement in the percentage extraction of p-xylene to different degrees. The percentage extraction of p-xylene from the o-/p-xylene 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 p-xylene from the o-/p-xylene mixture. The maximum enhancement factor, which is the ratio of the value in the presence and absence of a hydrotrope, was determined for both cases. The Setschenow constant, ks, a measure of the effectiveness of a hydrotrope, was determined for each case. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.