Production of biodiesel using oil obtained from fish processing residue by conventional methods assisted by ultrasonic waves: Heating and stirring

The biofuels have great ecological advantages against the petroleum fuels, especially when they are obtained from residues with environmental pollution potential. So, the biodiesel was produced using oil from the fish processing residue collected in the Fishermen's Colony Z-3, Brazil, and the experiments were developed with two different methods for production of biofuels. The fish residue was thermally treated to extract the fatty material and the biodiesel was produced by the methods of heating, stirring, and heating and stirring assisted by ultrasonic waves. The best biodiesel was with heating and stirring method with yields of 92.37% and 97.95% with the reaction times of 30 and 60 min, respectively. The ultrasonic method provided the highest biodiesel yield at the sonication time of 2 min, at the frequency of 20 kHz. The biodiesel produced from the fish waste showed high concentrations of sodium, potassium and magnesium. Furthermore, the production of biodiesel from a potential residue that can contaminate the environment, such as fish residue, promotes a social and economic increment in a community like Fishermen's Colony Z-3.