Calculation of constant overall composition phase diagrams involving fluid and solid phases

S.B. RODRIGUEZ-REARTES; M.S. ZABALOY

Ciudad Autónoma de Buenos Aires

Congreso; VIII Congreso Argentino de Ingeniería Química. CAIQ-2015; 2015

ASOCIACIÓN ARGENTINA DE INGENIEROS QUIMICOS

In this work we studied the heterogeneous region of computedsolid-fluid equilibrium isopleths of a binary system, by resorting tocalculated constant solidified-fraction curves. We used a model for thephase behavior of the highly asymmetric system carbon dioxide +medroxyprogesterone acetate. The model is applicable in wide ranges ofconditions. As generally done for constant overall composition mixtures, wecomputed phase envelopes (with fluid-fluid equilibrium (FFE), and solidfluidequilibrium (SFE) segments), and we also calculated appropriatesegments of solid-fluid-fluid equilibrium (SFFE) curves. Finally, forachieving a more complete characterization of the heterogeneous region ofthe computed solid-fluid equilibrium isopleths, we calculated severalconstant solidified fraction curves (= constant quality lines = level curves).The computations carried out suggest the existence of complex patterns ofbehavior for phase equilibria involving fluid and solid phases. The proposedapproach can be applied to any other binary system which presentsprecipitation, in pure form, of the heavy compound.