2025 Volume 51 Issue 4 Pages 89-95
Biofuel production from microalgae has the problem of consuming large amounts of energy for centrifugation and drying when harvesting the microalgae. To avoid centrifugation, flocculants can be used to harvest microalgae from the culture medium. Furthermore, lipids can be extracted from “wet” microalgae by using liquefied dimethyl ether (DME). However, the impact of flocculants on the lipid extraction process has not been studied, and there is concern that flocculants may contaminate the lipids and reduce the extraction yield. In this study, we recovered Pleurochrysis carteraew, a model species of microalgae, using three cationic polymer flocculants. Then, we investigated the impact of the flocculant on the lipid extraction by liquified DME. The results showed that high cationic flocculants decreased the yield of lipids, whereas low cationic flocculants did not inhibit lipid extraction by liquefied DME. Analysis of surface functional groups revealed that the flocculant did not contaminate the lipids. Therefore, the low cationic flocculant C510 could be used in conjunction with lipid extraction from P.carteraew by liquefied DME.
