Valorization of Restaurant Waste Oil Over Cow-bone Doped Siliceous Termite Hills Catalysts Towards Biodiesel Production

Abstract

Treated termite hill is a potent heterogeneous catalyst in the synthesis of biodiesel from restaurant waste oil (RWO). Two catalysts (raw cow-bone supported on silica; R-SC1.5 and calcined cow bone supported on silica; K-SC1.5) were developed and used in biodiesel production. The maximum conversion of RWO was 95.12 % using K-SC1.5 at reaction time 2.5 h, methanol to oil ratio 9:1, temperature 65°C and catalyst loading of 2 %w/w. The prepared catalysts were characterized using SEM, EDAX, FTIR, XRD and BET analysis. The kinetics of the RWO with R-SC1.5 and K-SC1.5 was further studied. The Ea and A were found to be 41.4 kJ mol− 1, 53.41 kJ mol− 1 and 2.24 ×104 min− 1, 2.29×106 min− 1 respectively. The transesterification reaction adhered to first order law, while physicochemical properties were within ASTM limits. Reusability of K-SC1.5 was also examined, which revealed effectiveness up to 5 reuses without significant reduction in biodiesel yield.