Particularly, the influence of burning temperature on the loading capability and biodiesel productivity has never been reported.
In the present work,we attempt to develop novel, low cost and highly efficient catalysts derived from the two waste materials of eggshell and RHA for the transesterification of palm oil. Furthermore, the physicochemical properties of the prepared catalysts were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometer, N2 adsorption–desorption (BET), the Hammett indicator method, scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDS). Meanwhile, the effects of catalyst preparation conditions (such as RH treatment temperature, the loading of calcined eggshell (CE) on the RHA, and the calcination temperature of eggshell-loaded RHA), reaction conditions (such as reaction time, methanol-to-oil molar ratio and catalyst loading) and the catalyst reusability were carefully studied.