TITLE:
Effect of Soaking Pre-Treatment on Reactive Extraction/in situ Transesterification of Nannochloropsis occulata for Biodiesel Production
AUTHORS:
Kamoru A. Salam, Sharon B. Velasquez-Orta, Adam P. Harvey
KEYWORDS:
Pre-Soaking, Microalgae, Cell Disruption, Glycerol, Transesterification, in situ Transesterification (Reactive Extraction)
JOURNAL NAME:
Journal of Sustainable Bioenergy Systems,
Vol.7 No.4,
October
23,
2017
ABSTRACT: Microalgal phospholipid bilayer contributes to the molar excesses of methanol
and high acid concentration required in reactive extraction to achieve high
fatty acid methyl ester (FAME) yield. This study reports an investigation into
the effects of pre-soaking Nannochloropsis occulata in methanol at 600:1 and
1000:1 methanol to oil molar ratios prior to acid-catalyzed in situ transesterification
at 8.5:1 and 15:1 H2SO4 to oil molar ratios on the FAME yield. The
results showed that the pre-soaked Nannochloropsis occulata produced a
higher FAME yield at the two tested methanol to oil molar ratios and acid
concentrations than the un-soaked, resulting in a reduction in methanol volume
and acid concentration. A maximum FAME yield of 98.4% ± 1.3% was
obtained for the pre-soaked Nannochloropsis occulata at 1000:1 methanol to
oil molar ratio and 15:1 H2SO4 to oil molar ratio. Both the phosphorus mass
balance and conversion of the isolated phospholipids into FAME revealed that
pre-soaking solubilizes the phospholipid bilayer to some degree, and contributes
to an increased FAME yield.