Lipid extraction from Chlorella vulgaris by molten-salt/ionic-liquid mixtures

Abstract

In this study, lipid extraction from Chlorella vulgaris was performed by using mixtures of molten salt and ionic liquid. The yield-enhancing effects of blending of molten salt with ionic liquid were investigated. Among the three molten salts (Zn(NO3)2·6H2O, Mg(ClO4)2·6H2O, and FeCl3·6H2O), FeCl3·6H2O showed a high lipid extraction yield (113.0mg/g cell) and good reaction performance. When FeCl3·6H2O was mixed with [Emim]OAc (5:1, w/w), the lipid extraction yield increased to 227.6mg/g cell, a performance similar to that of single [Emim]OAc (218.7mg/g cell). When lipid was extracted by the FeCl3·6H2O/[Emim]OAc mixture at a 5:1 (w/w) blending ratio, 90°C temperature, and 1h duration, the fatty acid content of the extracted lipid was 981.7mg/g lipid, indicating less than 2% impurity. The lipid extraction from C. vulgaris was improved by the synergistic effects of molten salt and ionic liquid with different ions.