The results illustrated in Fig. 11 show that number of stages
decreases while the solvent-to-feed ratio increases as the reflux
ratio increases. A high value of Nth leads to a low solvent flow rate,
thus reducing the column internal diameter. A low value of Nth
leads to high solvent flow rates, thus increasing the column internal
diameter. The results show that point C (T = 353K, P = 26 MPa) is
associated with a higher number of stages and greater amounts of
solventthanpointsAandBand,hence, itmay be discarded.Boththe
minimum reflux ratio min and minimum number of stages Nth,min
of point A are slightly higher than point B. However, point A needs
higher amounts of solvent. Thus, more information is needed to
select the point or points to be used for further extraction experiments,
as the diagram illustrated in Fig. 10 can only provide a
qualitative estimation about the separation design variables under
investigation.