Characterization of Eggshell: A Heterogeneous Catalyst in Transesterification of Sand Apple (<i>Parinari polyandra</i>) Seed Oil

Abstract

The objective of this study was to characterize a low cost heterogeneous catalyst from the transesterification of sand apple (Parinari polyandra B.) biodiesel. Sand apple fruits were processed and oil was extracted using solvent extraction method. Raw eggshells were calcined at 800°C for 120 min in the muffle furnace. Surface properties of the raw and calcined eggshell were characterized using Fourier Transformed Infrared Radiation (FTIR) and X-Ray Fluorescence (XRF). Transesterification of the Sand Apple Oil (SASO) with ethanol in the presence of the calcined catalyst to produce ethyl ester and glycerol were optimized using Central Composite Design at different temperatures and time. Reactants for the transesterification process were the raw SASO and anhydrous ethanol. The study shows that raw eggshell was more stable with hydrogen bond form at 2,724 cm^-1an while oil yield of 53.13 % was obtained from sand apple kernels. Ethyl ester yield of 90% was obtained from SASO. The results of transesterification shows the maximum biodiesel yield of 90% was obtained at reaction temperature of 65°C and time of 120 min, while the minimum yield of 70% was obtained at temperature of 55°C and time of 60 min; indicating that biodiesel increase with increase in time. Similarly, yield of ethyl ester of SASO also increased when the reaction temperature increased. The percentages of biodiesel yield obtained from SASO transesterification in this study showed that sand apple is promising oil for biodiesel production as compared with other vegetable oil crop obtained in previous studies