Biodiesel production from macro algae as a renewable energy source

(Biodiesel is monoalkyl esters of long-chain fatty acids produced from renewable resources like plant oils or animal fats through transesteri fication. The biodiesel should meet the ASTM D6751 standard specifications for the application as an alternative fuel. The transesterification is the process of removing the glycerines and combining fatty acid of vegetable oil (triglycerides) with monoalcohol to lower the viscosity of the fuel. Macroalgae are one of the inexpensive sources of oil feedstock for biodiesel production. Unlike other feedstock for biodiesel production, macroalgae can grow in places away from the farmland and forests and thus minimizing the damages caused to the food chain system). This research was conducted to study the oil extraction from macroalgae, conversion of algae oil to biodiesel, characterization of biodiesel and the performance of the diesel engine using the algae oil biodiesel blends. The algae oil was extracted by hexane solvent extraction method from six species (L. Epiphytic, Cladophora, Agardhiella, Gracilaria, Spirogyra and Bryopsis Pennata) of macroalgae. Agardhiella had highest 0.89 % (v/w) oil content in fresh and 6.60% in dry basis. The measured Free Fatty Acid (FFA) in extracted oil was below 4%. Biodiesel was produced through base-catalysed transesterification of different process. The highest yield was found 92 % (v/v) at methanol to oil ratio 4: 1, catalyst (KOH) 1.0 % (w/v) in heating with continuous stirring. The fuel properties and FTIR spectrum of algae biodiesel were similar to petroleum diesel. Biodiesel blends with petroleum diesel ranging from BO (100 % petroleum diesel) to B30 (30% biodiesel + 70% petroleum diesel) were prepared to carry out the engine performance test. The results showed that the specific fuel consumption increased as biodiesel percentages increase in fuel blends. The engine brake power was slight higher than ordinary diesel and decreased as engine speed increases. The exhaust emission tests showed that the macroalgae oil biodiesel provides significantly reducing harmful emissions of carbon monoxide (CO), nitrogen oxides (NOx) and hydrocarbon (HC) particles