Incorporation of CuO on the αFe2O3 nanoparticles as a heterogeneous catalyst for conversion of waste cooking oil into biodiesel
Atefeh Rezaeifar, Mohsen Mansouri, Basir Maleki
Abstract
This study focused on generating biodiesel from waste cooking oil (WCO) employing an αFe₂O₃/CuO nanocatalyst synthesized via a co-precipitation method. Several characterization techniques, including FTIR, XRD, SEM-EDX, BET, and TEM analyses, were applied to scrutinize the features of the fabricated nanocatalyst. The results confirmed the successful incorporation of CuO into the αFe₂O₃ structure. BET analysis further revealed that the addition of CuO nanoparticles significantly enhanced the catalyst's surface properties, increasing the number of active sites available for transesterification reactions. Besides, the αFe₂O₃/CuO nanocatalyst exhibited a specific surface area of 334 m²/g, highlighting its high surface availability for catalytic activity. The process was statistically optimized using response surface methodology (RSM) with a Box-Behnken design (BBD) to assess the influence of critical reaction parameters. Vital parameters evaluated included temperature (50-70 °C), methanol/WCO molar ratio (8-14 mol/mol), and catalyst loading (1-3 wt%). Moreover, ANOVA results indicated that the methanol/WCO molar proportion had the most remarkable effect on biodiesel production efficiency, with an F-value of 337.11. Under optimal conditions reaction time of 3 h, methanol/WCO molar ratio of 11, αFe₂O₃/CuO dosage of 2 wt%, and temperature of 60 °C a highest biodiesel yield of 94.27% was achieved. Additionally, the reusability assessment of the αFe₂O₃/CuO nanocatalyst demonstrated notable stability, with only a 12% reduction in efficiency observed over seven cycles. This research demonstrates that αFe₂O₃/CuO nanocatalysts, owing to their unique properties, have the potential to serve as highly effective heterogeneous catalysts for transesterification.