Biodiesel production from waste cooking oil using magnetic bifunctional calcium and iron oxide nanocatalysts derived from empty fruit bunch

Magnetic bifunctional nanocatalyst supported on activated carbon (AC), CaO-Fe2O3/AC was synthesized via wet impregnation method and utilized for catalytic transesterification of waste cooking oil (WCO). A series characterization techniques were performed to determine acid-base properties, magnetism, thermal stability, crystallinity, chemical composition, surface morphology the catalyst. The BET analysis showed that CaO-Fe2O3 catalysts had specific areas pore sizes (?5 nm) suitable reaction. optimized catalyst, CaO(10%)-Fe2O3(10%)/AC, possessed significant acidity basicity desorption 18532 ?mol g?1 2653 g?1, respectively, which contributed maximum biodiesel yield 98.3% at following reaction conditions: 3 wt%, catalyst loading, 18:1 methanol molar ratio 65 °C h Furthermore, magnetism CaO(10%)-Fe2O3(10%)/AC 7.59 emu/g, facilitated high recovery rates from mixture by magnetic decantation. Reusability experiments revealed a stability (FAME > 80%) least six consecutive cycles. Biodiesel confirmation Fourier transform infrared spectroscopy 1H-nuclear resonance strong C=O absorption band 1774 cm--1 singlet methoxy proton signal 3.7 ppm. Lastly, fuel properties met American standard ASTM 6751 with low kinetic viscosity 3.42 mm2s?1 flash point 134 °C.