INVESTIGADORES
ZABALOY Marcelo Santiago
congresos y reuniones científicas
Título:
Modeling the Fluid Phase Equilibria of Asymmetric CO2 – Hydrocarbon Systems using a Consistent Cubic Composition Dependency
Autor/es:
M. CISMONDI; J.M. MOLLERUP; M.S. ZABALOY
Lugar:
Cannes, France
Reunión:
Simposio; 23rd European Symposium on Applied Thermodynamics (ESAT2008). May 29th to June 1st 2008; 2008
Institución organizadora:
Laboratoire De Thermodynamique Des Separations - E.N.S.I.C.
Resumen:
The models for representing phase equilibria and physico-chemical properties of asymmetric systems require more flexible mixing rules than the classical quadratic van der Waals (vdW) mixing rules. Cubic mixing rules (CMRs), implemented as a natural extension of the classical mixing rules, constitute the simplest alternative among different flexible approaches. They have the advantage of allowing correlation of multicomponent data by fitting ternary interaction parameters, while leaving invariant the description of the constituent binary systems. If preferred, or if multicomponent data are not available, ternary interaction parameters can be consistently estimated from binary parameters. In a previous fundamental study of the possibilities that cubic mixing rules offer we considered a particularly difficult system, i.e., the system CO2 + n-Hexadecane, and showed that CMRs achieve a better description of the phase equilibria for this system than quadratic mixing rules, when using a unique set of carefully regressed temperature-independent interaction parameters. However, the capability that we expect for the CMRs, for a good representation of phase equilibria in wide ranges of temperature and pressure, should become more evident if we introduce temperature dependent interaction parameters. This is because CMRs, on their own, provide flexibility with respect to composition, although not to temperature. In this work we explore the possibilities that CMRs offer when coupled to temperature-dependent interaction parameters. We study here an asymmetric CO2 + n-alkane system paying attention to its global phase equilibrium behavior. To that end, we use our in-house powerful computer program GPEC, which is able to generate, in a single run, critical, azeotropic, liquid-liquid-vapor and pure-compound vapor pressure lines for a given binary system. GPEC can also generate, automatically, complete Txy and Pxy diagrams. GPEC is robust and fast. These features make possible quickly to acquire a deep understanding of the model behavior, over a wide range of conditions.