• biodiesel;
  • cetane index;
  • Chlorella vulgaris;
  • iodine value;
  • RSM


BACKGROUND: A major bottleneck in microalgal biodiesel production is lipid content, which is often low in microalgal species. The present study examines Chlorella vulgaris as a potential feedstock for biodiesel by identifying and evaluating the relationships between the critical variables that enhance the lipid yield, and characterizes the biodiesel produced for various properties.

RESULTS: Factors affecting lipid accumulation in a green microalga, Chlorella vulgaris were examined. Multifactor optimization raised the lipid pool to 55% dry cell weight against 9% control. When C. vulgaris cells pre-grown in glucose (0.7%)-supplemented medium were transferred to the optimized condition at the second stage, the lipid yield was boosted to 1974 mg L−1, a value almost 20-fold higher than for the control. The transesterified C. vulgaris oil showed the presence of ∼82% saturated fatty acids, with palmitate and stearate as major components, thus highlighting the oxidative stability of C. vulgaris biodiesel. The fuel properties (density, viscosity, acid value, iodine value, calorific value, cetane index, ash and water contents) are comparable with the international (ASTM and EN) and Indian (IS) biodiesel standards.

CONCLUSION:C. vulgaris biomass with 55% lipid content and adequate fuel properties is potentially a renewable feedstock for biodiesel. Copyright © 2011 Society of Chemical Industry