High pressure phase equilibrium for binary system dl-α tocopherol plus methanol

Pressure-composition isotherms for the system dl-alpha-tocopherol/methanol were measured, at four temperatures between 473.15 and 543.15 K and pressures up to 115 bar. The measurements were carried out using a constant volume static apparatus. For this system the isothermal curves reveal a regular pattern of behaviour. The experimental data, together with the system dl-alpha-tocopherol/carbon dioxide literature data were modelled with cubic equations of state using different mixing rules; the modified Redlich-Kwong-Soave model provided the better agreement with the experimental data for both systems. The results obtained for the system dl-alpha-tocopherol/carbon dioxide were compared with those reported in the literature. On the basis of the new experimental data and those of the literature and using a thermodynamic model, the behaviour of the ternary system dl-alpha-tocopherol/methanol/carbon dioxide was predicted. (C) 1998 Elsevier Science B.V.