Prior to applying the thermodynamic model to the study of the
internal reflux multi-stage process, some interesting features ofthe
thermodynamic behaviour of the system CO2 + FOEE at high pressure
are discussed here, analysing the results obtained in a series of
single-stage flash calculations.Atypical composition ofthe oil, suitable
for EPA and DHA production (see Table 1), was considered both
in these calculations and in the rest of this work [15]. S/F was set
equalto 60 g/g, which is a realistic value for the industrial supercritical
separation process of FOEE [14,15]. The flash calculations were performed for pressure values from 8 MPa up to approximately
20 MPa, for six different temperatures in the range (42–100) ◦C.
Even though kij(T) was calculated on the basis of experimental data
in the range (42–70) ◦C, the moderate extrapolation to a temperature
range moving away from the critical point (i.e., 70 ◦C–100 ◦C)
is expected to provide reliable qualitative trends.