Effect of Ultrasonic Waves on Aspire Biodiesel and Comparison of Its Properties with Petroleum Diesel

This study aimed to determine the effect of ultrasonic sound waves on modifying the chemical structure of biodiesel to bring its physical properties closer to petroleum diesel. In this direction, safflower oil was selected because its fatty acid composition is similar to fatty acid esters of petroleum diesel and is a sustainable source. Refined safflower oil, the free fatty acid content of which was determined, was reacted with methanol under NaOH catalyst to perform the transesterification reaction. After biodiesel production, samples were incubated in an ultrasonic bath for 60, 120, and 180 minutes. FTIR, density, free fatty acid content, flash point, viscosity, and cloud point analyses investigated the effect of incubation times on biodiesel's chemical structure and properties. FTIR spectra showed that ultrasonic sound waves partially decomposed fatty acid methyl esters and increased the number of volatile components in biodiesel. The flash point of biodiesel has been associated with a decrease of 89°C, and the low flash point is expected to increase fuel efficiency. Kinematic viscosity values were measured in the 3.4583-3.5115 mm²/s range, and density values were measured in the 0.8820-0.8872 g/ml range. These values show that biodiesel complies with national and international standards. As a result, the ultrasonic bath process applied to biodiesel showed a similar result to chemical modification methods by affecting the structure of fatty acid chains. Thus, it brought the physical properties of biodiesel closer to petroleum diesel. It is seen that this method is a more efficient alternative for biodiesel production because it does not use additional chemicals, and the process is faster. In conclusion, by increasing the production of the drought-resistant safflower plant, sustainable energy resources will be contributed, while its waste can be evaluated as animal feed. Ultrasonicated safflower biodiesel can also be used as an efficient, environmentally and mechanically friendly alternative fuel source.