Conversion of Fish Waste Oil into Biofuel: An Experimental Study

Egypt is famous for its fish wealth, given its large coasts and freshwater resources, especially of Nile Tilapia and Mugilid fish. It was estimated that domestic fish production increased from 889 thousand tonnes in 2005 to 1620 thousand tonnes in 2016. Thousands of tonnes of fish are consumed yearly, generating substantial amounts of fish waste and residues. Some 26% of the fish consumed is a typical waste. Fish wastes have a significant role in many processes and applications. They are used as feedstock for producing fish meals, a major by-product of fish waste oil. Fish oil is extracted for medical uses and is also used as a feedstock for producing biodiesel to be blended with conventional diesel to reduce hydrocarbon emissions. This research study aims to provide a reliable synthetic approach to producing aquatic biofuel as an efficient and renewable alternative energy source compared to crude oil fractions and their associated emissions that negatively impact the environment. In this research, fish oil waste has been extracted and purified before the transesterification reaction. Then, KOH was added as a catalyst to generate biodiesel and by-product glycerol, which is utilized in making soap and generating fertilizers. Aquatic biodiesel from aquatics was synthesized through a transesterification reaction, using fish waste oil from Nile tilapia and mugilid fish waste as fish waste oil. Reaction products are biodiesel and glycerol as by-products. For 75ml of fish waste oil, the methanol required for the reaction was estimated at 11ml, and the catalyst KOH was 0.88g. Reaction conditions were 60°C and 1-2 h. Several factors were investigated, including different concentrations and catalyst amounts, to optimize the reaction conditions and the biodiesel yield. Reaction products were separated into unreacted methanol, biodiesel, and by-product glycerol. Glycerol can find applications in soap and fertilizer production. The biodiesel produced was about 24 ml (32% yield) with a density of 0.8747g/ml. The yield of biodiesel can be optimized to reach typical ranges. If only 50% of domestic fish production is devoted to biodiesel production, the corresponding annual fish waste will be 421 thousand tonnes, yielding 84 thousand tonnes of fish oil extract.