Ternary liquid-liquid equilibria for mixtures of water,diisopropyl ether and iso-octane at different temperatures

Diisopropyl ether is an ideal fuel additive to replace methyl tert-butyl ether for its high octane number and less pollution.To assess the effect of diisopropyl ether addition on hydrocarbon-water mutual solubilities and to predict properties of mixtures of diisopropyl ether with gasoline substitution hydrocarbons,liquid-liquid equilibria for a(ter-)nary system of(water+diisopropyl ether+iso-octant) was measured at two different temperatures of 298.15 K and 308.15 K.The experimental liquid-liquid equilibrium data were satisfactorily correlated by using a modified form of the UNIQUAC model with ternary interaction parameters in addition to binary ones,and the correlated results give better agreement with the experimental results than those predicted with binary parameters only.