Synthesis and Characterization of CaO and KF Doped CaO (KF/CaO) Derived from Chicken Eggshell Waste as Heterogeneous Catalyst in Biodiesel Production

Chicken, duck and quail eggshell wastes were applied as raw materials for the preparation of heterogeneous catalyst. Prior to use, the calcium carbonate (CaCO3) content in the waste shell was converted to calcium oxide (CaO) by calcining at 700-900°C for 3hr. The physicochemical properties of the solid oxide catalyst were characterized by X- ray diffraction (XRD), energy dispersive X- ray fluorescence (EDXRF) and scanning electron microscope (SEM). Response surface methodology (RSM) was used to optimize the biodiesel production parameters. The optimum conditions of the independent variables in the present work were 8:1 molar ratio of methanol to oil, 25 wt% of calcined eggshell catalyst (calcined at 900ºC, 3hr), 65°C of reaction temperature at reaction time of 3hr. The predicted FAME yield was 92 % under the optimal conditions. Reusability of (CaO) catalyst was investigated. The KF doped CaO (KF/CaO) derived from chicken eggshell waste was prepared by reducing KF/CaO molar ratio from 0.45 to 0.003, synthesized by a wet impregnation method under microwave irradiation and used as heterogeneous catalyst in the transesterification of refined palm oil to get optimum FAME yield. The catalyst with the KF/CaO molar ratio of 0.006 and catalyst amount of 5 wt% exhibits the best performance under the optimum reaction conditions of preparation of biodiesel with the CaO catalyst using RSM. The doped catalyst could be reused at least four times with slight drop in activity which was attributed to the loss of active sites. The optimum reaction condition obtained for achieving maximum FAME yield of 95% were – 8:1 of methanol to oil molar ratio, 2.5 hr of reaction time, 5 wt% of catalyst amount and 65?C of reaction temperature