A comparative study on biodiesel production from biomass of three different species of algae

This study was aimed to compare the efficiency of biodiesel production by Chlorella emersonii, Cladophora fracta and Spirogyra. Algae were grown in artificial media consisting of wastewater for further growth and preservation. Harvested biomass of algae was placed in an oven at 60oC for drying and powdered to size of 1.0mm by grinding mill. Extraction of oils rom biomass of algae were carried out by hexane solvent in a Soxhlet extractor for 18 h and analyzed for various parameters such as fatty acid composition, iodine value, water contents, saponification value iodine value and acid value. Growth rate, lipid content, protein and carbohydrate contents of above mentioned species were measured in dried biomass o algae. Sodium methoxide prepared rom methanol and sodium metal was used as a catalyst or transesterification o extracted oil to methyl ester. Biodiesel yield was higher in Chlorella emersonii than Cladophora fracta and Spirogyra. Analysis of biodiesels produced through transesterification was carried out for various properties such as iodine values (49, 53 & 47), flash point (155, 156 & 160?), Specific gravity (0.912, 0.914 & 0.91), kinematic viscosity (4.7, 5.0 & 4.9), water content (17, 23 & 15 mg/kg), sulphur (0.01, 0.012 & 0.013 wt%), sulfated ash (0.004, 0.003 & 0.007 mass%), carbon residue (0.01, 0.02 & 0.01 mass%) cetain number (47, 49 & 51 min) and acid number (0.46, 0.5 & 0.49 mg.KOH/g) for Spirogyra, Cladophora fracta and Chlorella emersonii respectively. Additionally biodiesel properties of all samples were in accordance with ASTM standards.