화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.58, No.21, 9127-9139, 2019
Application of the Corresponding-State Law to the Parametrization of Statistical Associating Fluid Theory (SAFT)-Type Models: Generation and Use of "Generalized Charts"
Most of the Statistical Associating Fluid Theory (SAFT) and cubic equations of state (EoS) for nonassociating pure components obey the three-parameter corresponding-state law, meaning that the knowledge of three component-specific properties is a prerequisite to apply an EoS to a given pure species. Here, the methodology used to attribute values to EoS parameters is called "parameterization procedure". In this Article, it is shown that generalized charts, derived from the corresponding-state theory, can be used advantageously to parametrize SAFT models. SAFT EoS is a well-established class of models frequently used for process simulation. Depending on the EoS parameter set selected, most of SAFT EoS are likely to predict unrealistic phenomena (mainly, the presence of multiple critical points and three-fluid phase equilibrium regions in pure-component phase diagrams). Generalized charts can be used to detect whether such unrealistic phenomena affect pure-component phase diagrams in the temperature and pressure domains of interest. As a second application, it is proposed to parametrize SAFT EoS in the same spirit as cubic EoS: the three SAFT input parameters are fixed in order to exactly reproduce the experimental critical temperature, critical pressure, and one point of the vaporization curve through the acentric factor. It is shown that the procedure is simple to implement and opens the door to a large industrialization of SAFT EoS (i.e., the possibility to determine SAFT input parameters for any compound using a universal and univocal method).