TITLE:
In Situ Transesterification of Wet Marine and Fresh Water Microalgae for Biodiesel Production and Its Effect on the Algal Residue
AUTHORS:
Kamoru A. Salam, Sharon B. Velasquez-Orta, Adam P. Harvey
KEYWORDS:
Biodiesel (Fatty Acid Methyl Ester), Cell Wall, In Situ Transesterification, Surfactant, Surfactant Catalyst, Wet Microalgae
JOURNAL NAME:
Journal of Sustainable Bioenergy Systems,
Vol.6 No.2,
May
6,
2016
ABSTRACT: This article reports a high yielding technique of synthesizing zirconium dodecyl sulphate (“ZDS”)
for in situ transesterification of Nannochloropsis occulata and Chlorella vulgaris for fatty acid methyl
ester (FAME) production. ZDS produced a significantly higher FAME yield in N. occulata than
in C. vulgaris (p = 0.008). The varying performance of ZDS in the two species could be due to their
different cell wall chemistries. Sodium dodecyl sulphate (SDS) in H2SO4 for FAME enhancement
from the two species was also studied. Treatment with SDS in H2SO4 increased the FAME production
rate in both species. Residual protein content after the in situ transesterification in C. vulgaris
and N. occulata reduced respectively by 6.5% and 10%. The carbohydrate content was reduced by
71% in C. vulgaris and 65% in N. occulata. The water tolerance of the process when using H2SO4,
with or without SDS, was evaluated by hydrating the two species with 10% - 30% distilled water
(w/w dry algae). The FAME concentration began to diminish only at 30% water content in both
species. Furthermore, the presence of a small amount of water in the biomass or methanol increased
the lipid extraction efficiency, improving the FAME yield, rather than inhibiting the reaction.