Critical end line topologies for ternary systems

PISONI, GERARDO O.; CISMONDI, MARTÌN; CARDOZO-FILHO, LUCIO; ZABALOY, MARCELO S.

The Journal of Supercritical Fluids

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 p. 33 - 47

1872-8162

A ternary critical end line (T-CEL) is a line of Ternary critical end points (T-CEPs). T-CELs provide keyinformation on the phase behavior of ternary systems, i.e., they are boundaries for the ternary three-phase equilibrium. A ternary system may have several T-CELs. It is desirable to have available a robustalgorithm for computing complete ternary CELs, thus minimizing the need for user intervention. It is alsoimportant to reliably detect the key points where T-CELs originate or terminate. In this work, we proposeto apply a numerical continuation method (NCM) for the fast and robust computation of T-CELs. Wepresent calculated T-CELs for highly asymmetric systems showing the topologies that these lines define.We consider a model of the equation of state (EOS) type and use it over wide ranges of conditions. Suchranges are much wider than those previously considered in the literature. Our main conclusion is thatmodels for the fluid phase equilibria of ternary systems may predict, for a given system, several T-CELs ofvarying types and topologies. Some of such topologies have been observed for the first time in this work.