Nano-magnetic potassium impregnated ceria as catalyst for the biodiesel production

The main objective of this work comprises the investigation of biodiesel production from rapeseed oil using potassium impregnated Fe₃O₄-CeO₂ nanocatalyst. The various concentration of potassium impregnated Fe₃O₄-CeO₂ was screened for catalytic conversion of rapeseed oil to triglyceride methyl ester. The 25 wt % potassium impregnated Fe₃O₄-CeO₂ nanocatalyst showed best biodiesel production. Nanocatalyst was characterized by FTIR, XRD, SEM, TEM, BET and Hammett indicator for basicity test. The characterization of biodiesel was performed with GC-MS, ¹H and ¹³C NMR. Moreover, the optimum reaction parameters such as catalyst amount (wt %), oil to methanol ratio, reaction time and reaction temperature for transesterification reaction was analyzed and yield was determined by ¹H NMR. The maximum yield of 96.13% was obtained at 4.5 wt % catalyst amount, 1:7 oil to methanol ratio at 65 °C for 120 min. The properties of biodiesel such as acid value and kinematic viscosity were observed as 0.308 mg KOH/g and 4.37 mm²/s respectively. The other fuel parameters such as flash point and density were also determined. The reusability of catalyst was observed and it showed stability up to five cycles without considerable loss of activity. The recovery of excess methanol after transesterification reaction was achieved using distillation process setup.