Abstract: The two fresh water microalgae species namely Scenedesmus dimorphus and Scenedesmus obliquus were selected as biomass feedstocks for biodiesel production due to high accumulation of their neutral lipid content which mainly composed of three significant biodiesel fatty acids profile viz saturated fatty acids (SFA: ≈ 53%), mono unsaturated fatty acids (MUFA: ≈ 24%) and poly unsaturated fatty acids (PUFA: ≈ 20%). Both algae strains were cultivated with five different nitrogen nutrients via (NH4)2SO4 (ammonium sulphate: AS), NH4NO3 (ammonium nitrate: AN), KNO3 (potassium nitrate: PN), (NH2)2CO (urea: UR) and NaNO3 (sodium nitrate: SN) of concentration ranging from 0.02 to 0.3 M in agricultural medium. The transesterification of micro algal lipids with absolute ethanol medium in the presence of Ni/H2 catalyst and Ni(II)–Schiff base chelate promoter was carried out to yield more algal oil. The extracted biodiesel components were analyzed cost–effectively using UV–Vis,1H NMR, 13C NMR and GC–MS spectral characterization to explore their biodiesel potentiality. The results revealed that the extracted microalgae biodiesels are quite suitable for biodiesel production with higher oxidation stability and cetane number. Graphical Abstract: [Figure not available: see fulltext.] In this study, S. dimorphus and S. obliquus in the presence of five different nitrogen nutrients of concentration ranging from 0.02 to 0.3 M agar in cultural medium were observed to stimulate them to produce lipid for biodiesel generation. The transesterification of micro algal lipids with absolute ethanol medium in the presence of Ni/H2 catalyst and Ni(II)–Schiff base chelate promoter was carried out to yield more algal oil. The fatty acid composition of the extracted micro algal oils have been identified via UV–Vis, NMR and GC–MS spectral characterization techniques to investigate their biodiesel potentiality. It is noted that increased UR concentration (up to 0.3 M) can effectively enhances biomass production of S. dimorphus and S. obliquus as increased urea levels may enhances biomass production excluding cells may have a low lipid content, at times.
All Science Journal Classification (ASJC) codes
- Environmental Engineering
- Renewable Energy, Sustainability and the Environment
- Waste Management and Disposal