, direct wet extraction of microalgae is not
used on large scale in practice. In the study of Lardon et al.
(2009), the energy consumption for the wet extraction was estimated
by zooming in on the energy consumption of the dry extraction
proportionally to the processed volume. However, this may
result in an overestimation of the energy consumption as the cell
disruption energy requirements may differ for dry and wet extraction.
In the present study, cell disruption by a stirred ball mill and
solvent extraction using the Bligh & Dyer’s method (Bligh and Dyer,
1959) is taken as a reference. It is noted that, depending upon algae
species and solvent chosen, the cell disruption technology can even
be omitted. Here, it is assumed that approximately 0.5 MJ power is
needed for the cell disruption of one kilogram of 0.3 kg/L algae
slurry (Bunge et al., 1992). The lipid extraction is done under the
assumption that 2 g of mixing chloroform–methanol solvent (Lee
et al., 2010) is lost during the extraction of 1 kg microalgae slurry.