Pure caloric properties

The experimental determination of a fluid s T t and its inversion curve is difficult since very precise measurements of volumetric or caloric properties at conditions up to 5 times its critical temperature and 12 times its critical pressure. Experimental inversion curve data are therefore scarce, often unreliable [65], and mostly available only for pure fluids. 

For process simulators, a more sophisticated way is chosen which makes sure that the caloric properties are consistent even if chemical reactions occur. This is the case if the standard enthalpy of formation Ab° is taken as the reference point, This is explained in detail in the Section 3.1,5 and Chapters 6 and 12, The standard enthalpy of formation refers to the standard conditions To = 298,15 K and Po = 101325 Pa in the state of ideal gases (see Section 2.3), Therefore, the reference point for the specific enthalpy for a pure component is... 

Equations of state valid both for vapor and liquid phase as well as for pure components and mixtures provide all the necessary volumetric and caloric properties which are needed for process simulation except c p, where a correlation has to be provided. In case of the real liquid mixture behavior, the activity coefficient approach provides an alternative option which is still applied in most cases in chemical industry. This method is explained in detail in Chapter 5. It is more appropriate for low-pressure applications. Concerning the physical property calculation, it is more accurate, as all the properties are represented by separate correlations. The following section explains the correlation and estimation methods for the particular properties. 

Physical Properties of the Pure Compound (Colour, Melting Point, Boiling Point, Transport Phenomena, Calorical Data, Optical Properties, Spectral Information, Magnetic Properties, Electrical Properties, Electrochemical Behaviour). 

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