abstract
In this work, neutral lipids (NLs) extraction capacity and selectivity of six solvents were firstly compared.
In addition, an eco-friendly solvent combination of ethyl acetate and ethanol (EA/E) was proposed and
tested for lipid extraction from Chlorella sp. cultivated in outdoor raceway ponds and effect of extraction
variables on lipid yield were intensively studied. Results indicated that lipid extraction yield was
increased with solvent to biomass ratio but did not vary significantly when the value exceeded 20:1. Lipid
yield was found to be strongly dependent on extraction temperature and time. Finally, fatty acid profiles
of lipid were determined and results indicated that the major components were octadecanoic acid, palmitic
acid, linoleic acid and linolenic acid, demonstrating that the lipid extracted from the Chlorella sp.
cultivated in outdoor raceway ponds by EA/E was suitable feedstock for biodiesel production.