Thermodynamics of vapor-liquid equilibrium containing a series of alcohols and triethylamine

Abstract

The vapor-liquid equilibrium of binary systems of triethylamine with methylalcohol, ethylalcohol, n-propylalcohol, iso-propylalcohol, n-butylalcohol, sec-butylalcohol, and tert-butylalcohol are studied from 10°C to 40°C. Isothermal values of total vapor pressures of pure components and mixtures were obtained by using a modified static vapor pressure apparatus. The total pressure method combined with numerical integration of the Gibbs-Duhem equation was employed to calculate equilibrium vapor compositions, activity coefficients, excess thermodynamic functions such as G[superscript E], H[superscript E] and TS[superscript E]. Also V[superscript E] was directly calculated from the measured liquid densities of pure components and mixtures. The equilibrium characteristics, azeotropic phenomena, and deviations from solution ideality are investigated for each system. The excess free energies were represented with the orthogonal Tchebycheff polynomials. Also a correlation was made of the effect of molecular structure on the thermodynamic properties.