PRODUCTION OF ALGAL OIL AND - BIODIESEL AND ITS CHARACTERISATION

Abstract

roduction of bio-fuel especially from algae has been area of great interest for research which is very much relevant looking at the present scenario where everybody is trying to find an ideal alternate to naturally available petroleum energy resources. Production of biodiesel from algae as feedstock is more economical than any other biomass used as feedstock. It is so as some of the algal species studied have much better lipid content quantitatively and there growth rate is significantly enormous. Though large amount of work has been done on algal biodiesel production through dry algae process, not much work has been done using wet algae biomass as feedstock. In this thesis project, techniques to produce biodiesel from algae were studied and out of all the known techniques, solvent extraction and ultrasonic extraction were used to produce algal oil from wet algae containing around 55% of water and further biodiesel by transesterification process. Aim of the experiments done was to develop optimized technique for extraction of lipids from algae. A comparison was drawn between algal oil and biodiesel produced from solvent extraction using soxhlet apparatus, solvent extraction using flask-condenser-stirrer setup and ultrasonic extraction. Hexane was used as solvent for extraction of lipids from algae in all three processes. Amount of algal oil produced per gram of wet algal biomass was calculated for each extraction process and compared with estimated amount. Algal oil produced was transesterified with methanol under basic conditions using sodium hydroxide. Characterization of algal oil samples and biodiesel samples was done which include determination of density, aniline point, flash point, fire point and calorific value. Analysis part includes FTIR spectra of algal biomass samples (before and after extraction), algal oil and biodiesel samples, GC-MS of biodiesel samples recovered in three processes, XRD analysis of fresh dried algae, Fe-SEM of dried fresh and used algae samples and TLC of oil and biodiesel samples. Algae biomass left after algal oil extraction can be used further for bioremediation purpose for cleaning waste water or as animal feed.