Oil extraction from microalga Nannochloropsis sp. with isopropyl alcohol

YAO LINXING; GERDE JOSE A.; WANG TONG

Long Beach, California

Conferencia; 103rd AOCS Annual Meeting & Expo; 2012

American Oil Chemists' Society

An environmentally friendly extraction of microalgal oil and non-lipid biomass was investigated. Hot isopropanol (IPA) was used to extract oil from Nannochloropsis spp., leaving the majority of non-lipid biomass in a cake fraction. Extraction procedures with or without a dewatering step (DW) were compared. Effects of dewatering condition, IPA concentration, and sonication pretreatment on the oil and biomass yield were studied. The dewatering condition with high water-to-alcohol ration (2:1)and mild mixing (1-min gentle shaking) had less oil loss in the DW fraction than that with a low water-to-alcohol ratio (1:1) and vigorous mixing (30-min and 300 rpm shaking). When sonicated algae were used, the difference in oil loss between the above two dewatering conditions was greater. Without dewatering, a 70% (w/w) IPA solvent extracted 87 (one-time extraction) or 97% (two-time extraction) of the total oil in the intact algae cells, similar to the yields obtained from 87 or 95% IPA solvents, but required the least amount of IPA. With sonicated algae cells, the 70% IPA solvents extracted slightly less oil than 87 or 97% IPA. About 66% non-lipid biomass was recovered in the cake fraction.