Effects of ionic liquid mixtures on lipid extraction from Chlorella vulgaris

• Published in: Renewable energy 2014-05, Vol.65, p.169-174
• Main Authors: CHOI, Sun-A, OH, You-Kwan, JEONG, Min-Ji, SEUNG WOOK KIM, LEE, Jin-Suk, PARK, Ji-Yeon
• Format: Article
• Language: English
• Subjects: Applied sciences; Chlorella vulgaris; Energy; Exact sciences and technology; Natural energy
• ISSN: 0960-1481; 1879-0682
• DOI: 10.1016/j.renene.2013.08.015

In this study, pre-biodiesel-production lipid extraction from microalgae (Chlorella vulgaris) was performed. The yield-enhancing effects of ionic liquid blends on the lipid extraction were investigated. The initial fatty acids content of the C. vulgaris was 292.2 mg/g cell. The lipid extraction yield using single ionic liquids was compared with the yield obtained with organic solvents and ionic liquid mixtures, respectively. The yield by hexane-methanol solvent was 185.4 mg/g cell. Among the 12 ionic liquids, 1-ethyl-3-methyl imidazolium acetate, 1-ethyl-3-methyl imidazolium diethylphosphate, 1-ethyl-3-methyl imidazolium tetrafluoroborate, and 1-ethyl-3-methyl imidazolium chloride showed high (>200.0 mg/g cell) lipid extraction yields. Although the yields of 1-ethyl-3-methyl imidazolium ethyl sulfate and 1-ethyl-3-methyl imidazolium thiocyanate were only 60.5 and 42.7 mg/g cell, respectively, the yield for their mixture (weight ratio of 1:1) was improved to 158.2 mg/g cell. Similarly, whereas the lipid extraction yield of 1-ethyl-3-methyl imidazolium hydrogen sulfate was just 35.2 mg/g cell, that for its mixture with 1-ethyl-3-methyl imidazolium thiocyanate (weight ratio of 1:1) was boosted to 200.6 mg/g cell. Overall, the synergistic effects of the ionic liquid mixtures with different anions improved the lipid extraction yield of C. vulgaris.