CALORIMETRIC MEASUREMENTS FOR MODELING THERMODYNAMIC PROPERTIES OF PURE FLUIDS AND FLUID MIXTURES

Recent progresses in calorimetric techniques are reviewed and some typ ical measurements are used to illustrate the importance of such data t o further develop either equations of state for pure fluids, or group contribution based models for fluid mixtures. Heat capacities of gases , pure fluids and fluid mixtures can be easily measured from ambient t emperature to almost 600 K at pressures up to 30 MPa. Similarly, heats of mixing are obtained in the same ranges of temperatures and pressur es. In addition calorimetric measurements of pressure effects, up to 3 00 MPa, by the newly established technique, transitiometry, yield ther mal expansion coefficients of gases and fluids up to critical points. Synthetic natural gases acid binary as well as ternary nonelectrolyte mixtures serve to show how such data constitute severe tests for compa rison with theoretical models.