The ternary system composed of phenol, m-cresol and supercritical carb
on dioxide is characterized by unusual phase behaviour. In fact the te
rnary diagram shows five distinct regions: a three phase region of sol
id-liquid-gas, two two phase regions liquid-solid and liquid-gas, and
two single phase regions liquid and gas. In addition when pressure was
increased and temperatures were below the temperature of fusion of ph
enol, it was observed that the carbon dioxide causes recrystallization
of phenol from the liquid phase. To understand and to describe all th
ese phenomena, several experimental measurements were performed and ar
e reported in this paper. Finally, using all the available data for th
e pure compounds as well as for the three binary sub-systems, a modifi
ed Peng-Robinson Equation of State was parametrized and then used to d
escribe, at least qualitatively, the multicomponent multiphase behavio
ur in the whole range of composition under different values of pressur
e and temperature.