Biodiesel production from Nannochloropsis gaditana lipids through transesterification catalyzed by Rhizopus oryzae lipase
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URI: http://hdl.handle.net/10835/15223
DOI: https://doi.org/10.1016/j.biortech.2015.12.036
DOI: https://doi.org/10.1016/j.biortech.2015.12.036
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Navarro López, Elvira; Robles Medina, Alfonso; González Moreno, Pedro Antonio; Esteban Cerdán, Luis; Martín Valverde, Lorena; [et al.]Date
2015-12-13Abstract
Biodiesel (fatty acid methyl esters, FAMEs) was produced from saponifiable lipids (SLs) extracted from wet Nannochloropsis gaditana biomass using methanolysis catalyzed by Rhizopus oryzae intracellular lipase. SLs were firstly extracted with ethanol to obtain 31. wt% pure SLs. But this low SL purity also gave a low biodiesel conversion (58%). This conversion increased up to 80% using SLs purified by crystallization in acetone (95. wt% purity). Polar lipids play an important role in decreasing the reaction velocity - using SLs extracted with hexane, which have lower polar lipid content (37.4% versus 49.0% using ethanol), we obtained higher reaction velocities and less FAME conversion decrease when the same lipase batch was reused. 83% of SLs were transformed to biodiesel using a 70. wt% lipase/SL ratio, 11:1 methanol/SL molar ratio, 10. mL t-butanol/g SLs after 72. h. The FAME conversion decreased to 71% after catalyzing three reactions with the same lipase batch
Palabra/s clave
biodiesel
microalgae
intracellular lipase
Rhizopus oryzae
transesterification