Microwave-assisted transesterification of waste cooking oil using zinc ferrite catalyst for biodiesel production

Abstract

Spinel nanomaterial of ZnFe₂O₄ has been successfully synthesised and its high crystallinity is confirmed by x-ray diffraction analysis in the Fd m space group with crystallite size of around 37.96 nm. The agglomerated nature of the sample is confirmed through SEM analysis and compositional analysis using EDS. The maximum yield of 94.66% biodiesel is obtained at 15 min, 50℃ temperature, 6 weight % catalyst, and 6:1 ethanol: oil conditions. The FTIR analysis and ¹H-NMR analysis of waste cooking oil and biodiesel of different yields confirm the different functional groups exist in the sample and the biodiesel. The physio-chemical properties of the biodiesel match well with the literature values. The reusability of the ZnFe₂O₄ confirms the yield of 80.9% after 3 cycles under the same reaction conditions.