As shown in Fig. 3a and b, the effect of the volumetric flow rate
of supercritical solvent (0.75–3.5 mL/min) on the extraction yield
during the scCO2 extraction of RHSO from waste oilseeds of the food
processing process was examined under the conditions of 30 MPa,
40 ◦C and 355< Dp < 500 m. As the highest extraction yield determined
as 16.5 g oil/100 g dry solid could be achieved for all flow
rate conditions examined, the flow rate of supercritical solvent has
no effect on the extraction yield. However, as seen in Fig. 3a, significant
increases are achieved in the extraction rate in the first
periods of the separation process as the flow rate of the supercritical
solvent increases. When the flow rate was increased from 0.75
to 3.5 mL/min, the optimal operating time decreased by approximately
5–fold and fell down to 30 min from 150 min. In this study,
when the extraction yields achieved with different volumetric flow
rates was arranged according to the amount of supercritical solvent
passing through the filled column as shown in Fig. 3b. it was seen
that the extraction process was controlled in terms of solubility.
These results were also explained by some researchers [26–28,31]
that the equilibrium solubility of RHSO controls at least the first
part of extraction process.