Potential assessment of micro algal lipids: A renewable source of energy

Abstract

Two micro algal species namely Chlorella vulgaris (C1) and Chlorella sp. (C2) were selected for the viability of bio-oil production by transesterification in the presence of Ni/H2 catalyst supported with Ni(II)-Schiff base chelate promotor. By this method about 92% of low viscous bio-oil is obtained. Systematic characterizations of the extracted lipids with proximate, elemental and spectral techniques (FT-IR, UV-vis, GC-Mass, 1H NMR and 13C NMR) have been carried out to measure their composition profile. Thermogravimetry (TG/DTA) of the wet micro algal biomass, micro algal feed stock and bio-oil has also been performed to analyze their thermal behavior. In addition, scanning electron microscopic pictographs (SEM) were taken for analyzing the micro algal structure before and after the lipid extraction. The fuel properties of the extracted bio-oil were assessed using standard methods and compared to the standards. The bio-oil samples were tested for their remarkable in vitro biological and nuclease activities. In addition, the engine performance (brake specific fuel consumption and brake thermal efficiency) using five types of fuels namely diesel (B100), C1 micro algal bio-oil 20% blend (C1 B20), C2 micro algal bio-oil 20% blend (C2 B20), C1 micro algal bio-oil 50% blend (C1 B50) and C2 micro algal bio-oil 50% blend (C2 B50) and emission characteristics (CO2, NOx, exhaust and smoke) were studied for the bio-oil–diesel blends.