3.1.2. Effect of pressure and dielectric constant
In order to evaluate the effect of pressure on the efficacy of
SCCO2 extraction, two different stepped pressure configurations
(30, 40, and 50 MPa against 10, 20, and 30 MPa) were trialed. For
the higher-pressure extraction, the initial pressure of 30 MPa was
increased to 40 MPa at 80 min, followed by a further increment
to 50 MPa at 100 min. The lower-pressure extraction was carried
out in a similar arrangement, although pressure increments
occurred at different times: 40 and 80 min (see Fig. 2a). Each
extraction was performed at 60 C for 120 min using 20 g of dried
microalgae.