Transesterification of waste frying oil to methyl ester using activated Carbon supported Mg-Zn oxide as solid-base catalyst

Abstract

An activated carbon-supported Mg-Zn catalyst (Mg-Zn/AC) was prepared by using co-precipitation combined with incipient wetness impregnation methods. The catalyst structure was characterized by powder X-ray diffraction (XRD), N2 adsorption-desorption, Fourier transform infrared spectroscopy (FTIR), its microstructure was studied by the use of scanning electron microscopy (SEM)and the catalytic performance toward synthesis of methyl esters from waste frying oil (WFO) was investigated. The properties studied provided insight into the catalytic performance of the catalyst whereby the large surface area and pore volume of the support facilitated the distribution of metal particles and high dispersion of metals. The optimum reaction conditions were obtained by varying parameters such as methanol to oil ratio, catalyst loading, temperature and time. Under the conditions of reaction time of 5 h, temperature, 150 °C and catalyst dosage of 2.5 wt%, the methyl ester yield of >86% was achieved using 64 g of WFO, 38 g of methanol. The results showed that Mg-Zn/AC catalyst presented efficient activity during the transesterification reaction and is a promising heterogeneous catalyst for the production biodiesel fuel from vegetable oil feedstock.