The waste solid byproducts of Aurantiochytrium sp. oil are more than 20 mass%, discarded as rubbish, which have been found to contain a large amount of palmitic acid that exceeds more than 67 mass%, but it is difficult to transesterify into biodiesel, such as the waste cooking oil or waste engine oil. Chemical and biological transesterification are compared for discussing preliminary transesterification of waste solid byproducts of Aurantiochytrium sp. oil, which then can be used in the development of transesterification for the suitable mixture of biodiesel in this study. Overall, we successfully obtained more than 92 mass% transesterification rate from the solid byproducts of Aurantiochytrium sp. oil by chemical transesterification. Furthermore, thermal analysis, heat of combustion, flash point, and the kinematic viscosity of environmentally friendly diesel were conducted by differential scanning calorimetry (DSC), oxygen bomb calorimeter, flash point tester, and viscometer, respectively. These were compared with various proportions of biodiesel for mixing with petrodiesel in order to obtain the best condition of mixtures B10, (heat of combustion 43.4 MJ/kg; flash point 63.5 °C; kinematic viscosity 3.1 mm2/s) as a suitable environmentally friendly diesel of waste solid byproducts of Aurantiochytrium sp. oil.
