title: Two-step in situ biodiesel production from microalgae with high free fatty acid content.
abstract: The yield of fatty acid methyl ester (FAME) from microalgae biomass is generally low via traditional extraction-conversion route due to the deficient solvent extraction. In this study a two-step in situ process was investigated to obtain a high FAME yield from microalgae biomass that had high free fatty acids (FFA) content. This was accomplished with a pre-esterification process using heterogeneous catalyst to reduce FFA content prior to the base-catalyzed transesterification. The two-step in situ process resulted in a total FAME recovery up to 94.87±0.86%, which was much higher than that obtained by a one-step acid or base catalytic in situ process. The heterogeneous catalyst, Amberlyst-15, could be used for 8 cycles without significant loss in activity. This process have the potential to reduce the production cost of microalgae-derived FAME and be more environmental compatible due to the higher FAME yield with reduced catalyst consumption.
authors.affiliation: Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Dong
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Chao
authors.initials: C
authors.lastname: Miao
authors.forename: Yubin
authors.initials: Y
authors.lastname: Zheng
authors.forename: Shulin
authors.initials: S
authors.lastname: Chen
mesh_terms: D056804:Biofuels / Q000382:microbiology*; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D002384:Catalysis / Q000187:drug effects; D002708:Chlorella / Q000187:drug effects / Q000378:metabolism*; D004951:Esterification / Q000187:drug effects; D004952:Esters / Q000032:analysis; D005230:Fatty Acids, Nonesterified / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D006878:Hydroxides / Q000494:pharmacology; D000432:Methanol / Q000032:analysis; D058086:Microalgae / Q000187:drug effects / Q000378:metabolism*; D017680:Potassium Compounds / Q000494:pharmacology; D013343:Styrenes / Q000494:pharmacology; D013696:Temperature; D013818:Thermogravimetry
chemical_list: D056804:Biofuels; D004952:Esters; D005230:Fatty Acids, Nonesterified; D006878:Hydroxides; D017680:Potassium Compounds; D013343:Styrenes; C528218:amberlyst-15; C029943:potassium hydroxide; D000432:Methanol