Production of biodiesel from algae

Biodiesel has gained much attention in recent years due to its eco-friendly nature, non-toxic characteristics, biodegradability and lower net carbon cycle compared to conventional diesel fuels. In the current study, potential algal specie Spirogyra were collected from different districts of Khyber Pakhtunkhwa, Pakistan and employed as a feedstock for biodiesel production. In the first step, oil from algae specie was extracted using n-Hexane and Di-ethyl Ether as solvents, while in the second stage; extracted oil was converted into biodiesel via transestrification reaction. The effects of solvent to oil ratio, size of algal biomass and contact time were studied on the percentage yield of oil extracted. The maximum extracted oil was 0.09 fraction of biomass, by using a blend of both solvents at solvent to biomass ratio of 3.5, algal biomass size of 0.4 mm and contact time of 24 hours. While in transestrification reaction, effects of molar ratio, temperature, reaction time and amount of catalyst (Sodium Hydroxide) were evaluated on the amount of biodiesel produced. Almost 95% conversion of extracted oil into biodiesel was achieved after 25 minutes of contact time at 60 °C with catalyst amount of 0.5% weight of oil and oil to methanol ratio of 8.