Optimization of microwave-assisted biodiesel production using Iron (III) oxide - Calcium oxide / Activated charcoal derived from waste Asian green mussel shell as heterogeneous catalyst

Abstract

The primary objective of this study was to produce a heterogeneous iron (III) oxide (Fe2O3)-calcium oxide (CaO)/activated charcoal (AC) catalyst from Asian green mussel shell utilizing wet impregnation and calcination processes for biodiesel synthesis. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and the Brunauer-Emmett-Teller (BET) method were used to analyze the novel catalyst. Using a central composite design (CCD)-based response surface methodology (RSM), the process parameters such as catalyst quantity, reaction time, and microwave electrical power were optimized. The optimal reaction conditions were determined to be 1.07 wt.% of Fe2O3-CaO/AC, 6.42 min of reaction time, and 667 W of microwave electrical power. The published results imply that the heterogeneous catalyst has a great potential for the direct conversion of waste frying oil (WFO) to biodiesel, with the ability to reuse without reactivation. The development of Fe2O3-CaO/AC as a novel heterogeneous catalyst would facilitate the manufacture of biodiesel in an eco-friendly manner.