Calculation of Complex Phase Equilibrium Isotherms in Ternary Systems

G.O. PISONI; M. CISMONDI; L. CARDOZO-FILHO; M.S. ZABALOY

ALICANTE

Conferencia; X IBEROAMERICAN CONFERENCE ON PHASE EQUILIBRIA AND FLUID PROPERTIES FOR PROCESS DESIGN (EQUIFASE 2015); 2015

UNIVERSIDAD DE ALICANTE - ALICANTE ESPAÑA

Ref [1] describes an approach for computing binary (phase equilibrium) Txy and Pxy diagrams using,as starting point, information on previously computed univariant lines: critical and three-phase lines,and pure compound vapor pressure curves. Key points, relevant to the set temperature (or setpressure), are obtained from such lines. The key points are the limits of the isothermal (or isobaric)equilibrium phase envelope/envelopes, and/or the limits between the segments (liquid-liquid or vaporliquid)that make a phase envelope up. In such approach [1], the use of stability tests is minimized. Inthis work, an analogous methodology is tested for the case of ternary systems held at constanttemperature [ternary isotherm (TI)]. First, key points are obtained, and then proper phase equilibriumlines are computed. The goal is to test the performance of the methodology for a case of particularlycomplex ternary phase behavior.[1] M. Cismondi, M. Michelsen. Fluid Phase Equilibria 259 (2007) 228?234.