title: Extraction of saponifiable lipids from wet microalgal biomass for biodiesel production.
abstract: Saponifiable lipids (SLs) were extracted with hexane from wet biomass (86 wt% water) of the microalga Nannochloropsis gaditana in order to transform them into fatty acid methyl esters (FAMEs, biodiesel). The influence of homogenization pressure on SL extraction yield at low temperature (20-22 °C) was studied. Homogenization at 1700 bar tripled the SL extraction yield. Two biomass batches with similar total lipid content but different lipidic compositions were used. Batch 1 contained fewer SLs (12.0 wt%) and neutral saponifiable lipids (NSLs, 7.9 wt%) than batch 2 (21.6 and 17.2 wt%, respectively). For this reason, and due to the selectivity of hexane toward NSLs, high SL yield (69.1 wt%) and purity (71.0 wt%) were obtained from batch 2. Moreover, this extract contains a small percentage of polyunsaturated fatty acids (16.9 wt%), thereby improving the biodiesel quality. Finally, up to 97.0% of extracted SLs were transformed to FAMEs by acid catalyzed transesterification.
authors: Area of Chemical Engineering, University of Almería, 04120 Almería, Spain.
authors: María J
authors: MJ
authors: Jiménez Callejón
authors: Area of Chemical Engineering, University of Almería, 04120 Almería, Spain. Electronic address: arobles@ual.es.
authors: Alfonso
authors: A
authors: Robles Medina
authors: Area of Chemical Engineering, University of Almería, 04120 Almería, Spain.
authors: María D
authors: MD
authors: Macías Sánchez
authors: Area of Chemical Engineering, University of Almería, 04120 Almería, Spain.
authors: Estrella
authors: E
authors: Hita Peña
authors: Area of Chemical Engineering, University of Almería, 04120 Almería, Spain.
authors: Luis
authors: L
authors: Esteban Cerdán
authors: Area of Chemical Engineering, University of Almería, 04120 Almería, Spain.
authors: Pedro A
authors: PA
authors: González Moreno
authors: Area of Chemical Engineering, University of Almería, 04120 Almería, Spain.
authors: Emilio
authors: E
authors: Molina Grima
mesh_terms: D056804:Biofuels / Q000382:microbiology*; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D004951:Esterification; D005227:Fatty Acids / Q000032:analysis; D007700:Kinetics; D008055:Lipids / Q000302:isolation & purification*; D058086:Microalgae / Q000378:metabolism*; D011312:Pressure; D014867:Water
chemical_list: D056804:Biofuels; D005227:Fatty Acids; D008055:Lipids; D014867:Water
keywords: Biodiesel; Extraction; High-pressure homogenization; Microalga; Saponifiable lipid