Physical Properties and Spray Characteristics of Ultrasound-assisted Emulsion based on Ultra Low Sulphur Diesel and Biodiesel

Using fuels with a no-sulphur or limited-sulphur content for diesel engines has been considered an urgent issue in the reduction of pollution due to the difficulty of controlling sulphur emissions. In this experimental study, ultra-low sulphur diesel (ULSD) originating from fossil fuel and biodiesel from waste cooking oil (WOB) were mixed with ultrasonic assistance. The optimal mixing rate of ULSD and WOB, and the optimal distance of the ultrasound horn tip, were found as 65%:35% and 80 mm, respectively. After 15 minutes of ultrasonic treatment, a ULSD-WOB emulsion was formed, with the highest stability at around 99%, and its physical properties attained constant values. In addition, the spray characteristics of the ULSD-WOB emulsion, the WOB and the ULSD, including the spray penetration and cone angle, were examined and compared to those of fossil diesel fuel (DF). As a result, the ULSD-WOB emulsion produced with the assistance of ultrasound met the strict requirements of fuels used for diesel engines