Low‐temperature epoxidation of hybrid rice bran oil and oleic acid using natural zeolite catalyst

Abstract

Abstract This study investigates the low‐temperature epoxidation of a hybrid rice bran oil–oleic acid system using natural zeolite as a heterogeneous catalyst. The reaction was performed within the temperature range of 30–60°C, and its performance was evaluated based on relative conversion to oxirane (RCO), oxirane oxygen content (OOC), FTIR analysis, and kinetic modeling. The results show that the maximum RCO of 23.10% was achieved at 60°C, while a more stable RCO profile was obtained at 50°C with a peak value of 16.64%. At lower temperatures, RCO values remained limited, with 8.54% and 8.60% recorded at 30°C and 40°C, respectively. For oxygen carrier type, formic acid exhibited the highest RCO of 42.70%, followed by acetic acid (42.01%) and lactic acid (25.20%). The temporal profile of OOC showed a maximum experimental value of 0.9277 at 20 min before gradually declining. FTIR spectra confirmed the formation of epoxy groups with a characteristic absorption peak at ~825 cm −1 . Kinetic modeling using particle swarm optimization demonstrated good agreement between experimental and simulated data, with a low error value of 0.12. The results confirm the effectiveness of low‐temperature epoxidation using natural zeolite for producing bio‐based epoxide intermediates.