Measurement and correlation of the (vapor + liquid) equilibria of pure 4-ethylmorpholine, 1,2-dimethylisopropylamine and N,N-dimethylethanolamine, and their binary aqueous solutions

•Vapor pressures of 4-ethylmorpholine, DMIPA and DMAE and their aqueous solutions.•The investigated temperatures are from 273 K through 363 K.•The two first mixtures show positive azeotropic behavior and exhibit positive GE.•The third solution shows either positive or sinusoidal shape for GE.•The Wilson, NRTL and UNIQUAC models were applied.

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 < T < 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.