title: A whole biodiesel conversion process combining isolation, cultivation and in situ supercritical methanol transesterification of native microalgae.
abstract: A coupled process combining microalgae production with direct supercritical biodiesel conversion using a reduced number of operating steps is proposed in this work. Two newly isolated native microalgae strains, identified as Chlorella sp. and Nannochloris sp., were cultivated in both batch and continuous modes. Maximum productivities were achieved during continuous cultures with 318mg/lday and 256mg/lday for Chlorella sp. and Nannochloris sp., respectively. Microalgae were further characterized by determining their photosynthetic performance and nutrient removal efficiency. Biodiesel was produced by catalyst-free in situ supercritical methanol transesterification of wet unwashed algal biomass (75wt.% of moisture). Maximum biodiesel yields of 45.62wt.% and 21.79wt.% were reached for Chlorella sp. and Nannochloris sp., respectively. The analysis of polyunsaturated fatty acids of Chlorella sp. showed a decrease in their proportion when comparing conventional and supercritical transesterification processes (from 37.4% to 13.9%, respectively), thus improving the quality of the biodiesel.
authors.affiliation: LIP-MB Laboratory (LR11ES24), INSAT - University of Carthage, Tunisia.
authors.forename: Souhir
authors.initials: S
authors.lastname: Jazzar
authors.affiliation: Department of Chemical Engineering, University of Murcia, Campus of Espinardo, E-30071 Murcia, Spain.
authors.forename: Joaquín
authors.initials: J
authors.lastname: Quesada-Medina
authors.affiliation: Department of Chemical Engineering, University of Murcia, Campus of Espinardo, E-30071 Murcia, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Olivares-Carrillo
authors.affiliation: LIP-MB Laboratory (LR11ES24), INSAT - University of Carthage, Tunisia.
authors.forename: Mohamed Néjib
authors.initials: MN
authors.lastname: Marzouki
authors.affiliation: Department of Chemical Engineering, University of Almería, E-04120 Almería, Spain.
authors.forename: Francisco Gabriel
authors.initials: FG
authors.lastname: Acién-Fernández
authors.affiliation: Department of Chemical Engineering, University of Almería, E-04120 Almería, Spain.
authors.forename: José María
authors.initials: JM
authors.lastname: Fernández-Sevilla
authors.affiliation: Department of Chemical Engineering, University of Almería, E-04120 Almería, Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: Molina-Grima
authors.affiliation: LIP-MB Laboratory (LR11ES24), INSAT - University of Carthage, Tunisia. Electronic address: Issam.Smaali@insat.rnu.tn.
authors.forename: Issam
authors.initials: I
authors.lastname: Smaali
mesh_terms: D061249:Batch Cell Culture Techniques / Q000295:instrumentation*; D056804:Biofuels / Q000382:microbiology*; D018920:Coculture Techniques; D004867:Equipment Design; D019544:Equipment Failure Analysis; D004951:Esterification; D050356:Lipid Metabolism / Q000502:physiology*; D000432:Methanol / Q000302:isolation & purification / Q000378:metabolism*; D058086:Microalgae / Q000302:isolation & purification* / Q000378:metabolism*; D058433:Photobioreactors / Q000382:microbiology*; D011312:Pressure; D013696:Temperature
chemical_list: D056804:Biofuels; D000432:Methanol
keywords: Biodiesel; In situ supercritical transesterification; Microalgae isolation; Photobioreactor culture; Wet unwashed paste