Properties of waste-distilled engine oil and biodiesel ternary blends

This study aims to improve the fuel properties limitations of biodiesel which affect the engine performance characteristics in diesel engines. A ternary mixture simplex axial design model was used to determine the fuel properties of ternary blend mixture of waste distilled engine oil, waste cooking oil biodiesel, and petroleum diesel, and comparing it with existing physical properties models. The fuel properties namely: heating value, flash point, cetane number, density, and viscosity were determined by changing the composition in the ternary mixture design. Furthermore, the experimental data of the mixture model was fitted with existing viscosity, density, heating value, and flash point models. The viscosities were fitted with the Cragoe, Bingham, Arrhenius, and Kendall–Monroe viscosity models at 40 °C respectively. The best fit of the experimental data occurred in the following descending order: Arrhenius, Kendall–Monroe, Bingham, and Cragoe with R(2) values of 0.9771, 0.9529, 0.9508, and 0.6096, respectively. The density at 20 °C, heating value, flash point, and cetane number were fitted with Kay's model based on the mixing empirical equation. The results showed that these properties were well predicted by Kay's model mixing rule empirical model due to high values of R(2) of 0.9880, 0.978, 0.9929, and 0.961 respectively. The viscosity, density, heating value, and flash point of the ternary blend mixtures are within the American Society for Testing and Materials (ASTM) D 6751 and ASTM D 975 specifications range.