Liquid phase PVTx properties of binary mixtures of (water + ethylene glycol) in the range from 278.15 to 323.15 K and from 0.1 to 100 MPa. I. Experimental results, partial and excess thermodynamics properties

The coefficient of compressibility, k = ΔV/Vo, of {water (1) + ethylene glycol (2)} binary mixture was measured at pressures from 0.1 to 100 MPa and temperatures from 278.15 to 323.15 K over the whole concentration range. At all state parameters the following characteristics were calculated: excess molar volumes of the mixture, VmE; changes of excess molar Gibbs energy, ΔPo→PGmE; changes of excess molar entropy, ΔPo→PSmE; changes of excess molar enthalpy, ΔPo→PHmE; mixing enthalpy, HmE, of water with ethylene glycol at high pressure, and partial molar volumes of the components. It was shown that the coefficients of compressibility, k, sharply decreased over the concentration interval x2 = 0 –0.2, where x2 was ethylene glycol mole fraction, and further changed insignificantly. It was revealed that excess molar volumes were negative at all temperatures studied and went down with pressure increasing. The dependence of partial molar volumes of the mixture components on ethylene glycol mole fraction passes extreme at all isobars. Limiting partial molar volumes of water and ethylene glycol decrease with pressure growth. The mixture compression leads to its ordering due to new hydrogen bonds formation.