Production and characterization of biodiesel from the unicellular green alga<i>Scenedesmus obliquus</i>

Abstract

Regardless of whether biodiesel is represented in the form of oil from grains, agricultural crops, or microorganisms, it is a clean fuel depends mainly on biomass conversion. The present work indicates that the green microalga Scenedesmus obliquus showed higher biomass productivity of 0.15 g (CDW) L−1 d−1. The increase in NaCl concentration up to +100% caused an increase in growth, esterified fatty acid (EFA) content, and EFA productivity of S. obliquus. The decrease or increase of pH values reduced the growth, EFA content, and productivity. Biomass productivity increased from 0.06 g L−1d−1 under a light intensity of 80 μmol m−2s−1 to 0.1 g L−1d−1 at 160 μmol m−2 s−1. Biodiesel characterization showed that the iodine value of biodiesel of S. obliquus was 70 g iodine/100 g oil. Except viscosity, all biodiesel characteristics are in accordance with the European standards for fuel diesel (EN 590:1999). These results nominate S. obliquus as a promising candidate for biodiesel production by outdoor cultivation.