Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

The vapor pressures of (4-ethylmorpholine + water), (1,2-dimethylisopropylamine + water), (N,N-dimetylethanolamine + water) binary mixtures, and of pure 4-ethylmorpholine, 1,2-dimethylisopropylamine and N,N-dimethylethanolamine components were measured by means of two static devices at temperatures between {273 (or 283) and 333 (or 363)} K. The data were correlated with the Antoine equation. From these data excess Gibbs functions (GE) were calculated for several constant temperatures and fitted to a fourth-order Redlich Kister equation using the Barker s method. The (4-ethylmorpholine + water), and (1,2-dimethylisopropylamine + water) binary systems show positive azeotropic behavior. The aqueous solutions of 4-ethylmorpholine and 1,2-dimethylisopropylamine exhibit positive deviations in GE for all investigated temperatures over the whole composition, where the aqueous solution of N,N-dimetyhlethanolamine show a S shape for GE for (273.15 less than T less than 313.15) K. Additionally, the Wilson, NRTL or UNIQUAC models have been used and quite good results were obtained in the prediction of the total pressure.