title: Subcritical co-solvents extraction of lipid from wet microalgae pastes of Nannochloropsis sp.
abstract: In this paper subcritical co-solvents extraction (SCE) of algal lipid from wet pastes of Nannochloropsis sp. is examined. The influences of five operating parameters including the ratio between ethanol to hexane, the ratio of mixed solvents to algal biomass (dry weight), extraction temperature, pressure, and time were investigated. The determined optimum extraction conditions were 3:1 (hexane to ethanol ratio), 10:1 ratio (co-solvents to microalgae (dry weight) ratio), 90°C, 1.4 MPa, and 50 min, which could produce 88% recovery rate of the total lipids. In addition, electron micrographs of transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were conducted to show that the algal cell presented shrunken, collapsed with some wrinkles and microholes after SCE extraction. The main composition of total lipids extracted under the optimum conditions was TAG which represented more than 80%. And the fatty acid profile of triglycerides revealed that C16:0 (35.67 ± 0.2%), C18:1 (26.84 ± 0.044%) and C16:1 (25.96 ± 0.011%) were dominant. PRACTICAL APPLICATIONS: The reported method could save energy consumption significantly through avoiding deep dewatering (for example drying). The composition of the extracted lipid is suitable for the production of high quality biodiesel.
authors: Key Laboratory of Biofuels, Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences Qingdao, China.
authors: Min
authors: M
authors: Chen
authors: Tianzhong
authors: T
authors: Liu
authors: Xiaolin
authors: X
authors: Chen
authors: Lin
authors: L
authors: Chen
authors: Wei
authors: W
authors: Zhang
authors: Junfeng
authors: J
authors: Wang
authors: Lili
authors: L
authors: Gao
authors: Yu
authors: Y
authors: Chen
authors: Xiaowei
authors: X
authors: Peng