Transesterification of Palm Oil Catalyzed by Fresh Water Bivalve Mollusk (Margaritifera falcata) Shell as Heterogeneous Catalyst

A heterogeneous catalyst has been derived from a waste material of fresh water bivalve mollusk (i.e., Margaritifera falcata outer shell) for the transesterification of palm oil. The shell was washed, crushed, ground, and calcined at 850 degrees C to derive active CaO catalyst. The catalyst was characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), and differential thermal analysis/thermogravimetric (DT/TG) analysis. The DT/TG analysis showed the decomposition of calcium carbonate present in the shell at 780 degrees C. The XRD peaks for calcined shell were observed at 2 theta = 32.22 degrees, 53.53 degrees, and 64.03 degrees characteristics of CaO and showed high crystallinity. The textural structure of shell can be observed from the SEM images indicated that the structure of shell changed with calcination temperature. The FTIR absorption bands of the calcined shell were observed at 1471, 1090, and 874 cm(-1), which are attributed to the decrease of the reduced mass of the functional group attached to the CO32- ions. The waste driven (bivalve mollusk outer shell) catalyzed palm oil transesterification resulted in a high yield (90%) and conversion (98.2%) of biodiesel that was obtained at a 10:1 (methanol to oil) molar ratio and 4 wt % catalyst concentration at 60 degrees C in 5 h reaction time. The conversion of biodiesel was determined by H-1 NMR.