A potential alternative to the short path distillation process
is the fractionation using supercritical carbon dioxide (SCCO2). A
number of seminal studies dealing with semicontinuous processes
demonstrated that this solvent is capable of separating FOEE at
temperatures below 100 ◦C and pressures below 20 MPa, showing
a selectivity that mainly depends on the length of the carbon
chain, being the short chain esters preferentially solubilized. In
these processes, a batch of oil is charged in an extraction vessel and
SCCO2 is then passed through the charge. Since the solvent extracts
preferentially the short chain esters, the EPA and DHA esters are
concentrated in the raffinate oil remaining in the extraction vessel
[7,10–13].