Thermodynamic properties of the LiCl–H 2O system at vapor–liquid equilibrium from 273 K to 400 K

Abstract

A formulation of the thermodynamic properties of the LiCl–H 2O system at vapor–liquid equilibrium is presented in the form of separate Gibbs energy equations for the vapor and solution phases. Explicit thermodynamically consistent equations for density, isobaric heat capacity, enthalpy, entropy, enthalpy of dilution and osmotic coefficient are given. The pressure at vapor–liquid equilibrium is calculated from the condition of phase equilibrium. The description of the properties is valid from 273 K or from the crystallization line up to 400 K in temperatures and for solution composition from 0 to 50 wt% of LiCl in the solution, which is the region covewred by available experimental data. The thermodynamic properties of the gas phase are approximated by the properties of pure water vapor computed from the IAPWS formulation 1995. The Gibbs energy equation for solution is based upon a body of experimental data that have been critically assessed. Within the present study, 136 experimental works have been collected containing a total of 2921 data points on various thermodynamic properties of the LiCl–H 2O solutions. Gaps in the database are shown to give experimenters orientation for future research. The uncertainties associated with correlation are estimated to be ±0.4% for density, ±2.0% for pressure and ±2.4% for isobaric heat capacity. The uncertainty in values of enthalpy is estimated to be less than ±10 kJ kg −1 and less than ±0.03 kJ kg −1 K −1 for entropy. Values of the particular properties generated by the representative equations are provided to assist with the confirmation of computer implementation of the calculation procedure.