The Role of Thermodynamic Modeling

This pattern appears in the virial equation of state, in correlations of gas properties based on residual properties, and in correlations of liquid mixture properties based on excess properties. Another separation of reality takes a multiplicative form. 

This pattern is used to correlate gas volumes in terms of the compressibility factor, to correlate gas phase fugadties in terms of fugadty coefficients, and to correlate liquid mixture fugacities in terms of adivity coefficients. 

1 we noted that pure thermodynamics is not generally sufficient to solve engineering problems. Thermodynamics provides numerous relations among such quantities as temperature, pressure, heat capadties, and chemical potentials, but to obtain numerical values for those quantities, we must rely on experimental data—thermodynamics itself provides no numbers. 

The resulting models may be used in various applications, including chemical reaction equilibria, which is important to chemical reactor design, and phase equilibria, which arises in distillation, solvent extraction, and crystallization. But in addition to such traditional applications, thermodynamic models may also be used to help solve many other engineering problems, such as those involving surface and interfacial phenomena, supercritical extraction, hazardous waste removal, polymer and composite material development, and biological processing. 

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