A topological approach to mass barotropic phenomena in asymmetric mixtures

Flores, M.E.; Tardon M.J.; Bidart C.; Mejía A.; Segura H.

Abstract

Mass density inversion, a phenomenon also known as mass barotropy, corresponds to a singular behavior that directly affects the relative position of phases in heterogeneous mixtures when exposed to gravitational fields. In this contribution we introduce a topological description of the mass density inversions observed in asymmetric binary mixtures, a case that is appropriately exemplified by the evolution of the barotropy experimentally observed in carbon dioxide. +. hydrocarbon mixtures. From this basic example, necessary and sufficient conditions are deduced for exhibiting mass density inversions in direct relation with the global phase behavior of the mixture. Finally, the global phase diagram (GPD) predicted by the PC-SAFT equation is used for describing barotropic ranges in mixtures composed by carbon dioxide and hydrocarbons of increasing chain length, together with the specific effects that transitional mechanisms induce on the phenomenon. In excellent agreement with the available experimental data, results show that mass barotropy is present over ranges essentially involving Type III and IV systems. In addition, since the phenomenon is shown to appear also in Type II systems, it is concluded that mathematical double point (MDP) transitions do not necessarily control barotropic behavior. Finally, the occurrence of double critical end points satisfying the conditions of mass barotropy unequivocally explains the shift of barotropic points along the branch(es) of the liquid-liquid-gas line, as the alkane's chain length increases. © 2011 Elsevier B.V.

Más información

Título según WOS: A topological approach to mass barotropic phenomena in asymmetric mixtures
Título según SCOPUS: A topological approach to mass barotropic phenomena in asymmetric mixtures
Título de la Revista: FLUID PHASE EQUILIBRIA
Volumen: 313
Editorial: ELSEVIER SCIENCE BV
Fecha de publicación: 2012
Página de inicio: 171
Página final: 181
Idioma: English
URL: http://www.scopus.com/inward/record.url?eid=2-s2.0-82755171817&partnerID=40&md5=059b4c6cbb0f4ec819624066c8764b15
DOI:

10.1016/j.fluid.2011.09.030

Notas: ISI, SCOPUS