Enhanced Oxirane Formation in Palm Stearin–Oleic Acid Blend via Choline Chloride‐Mediated Epoxidation

This study presents a green epoxidation approach for a hybrid palm stearin–oleic acid system using a choline chloride‐mediated reaction environment to enhance oxirane formation. Nevertheless, conventional epoxidation approaches are often limited by oxirane ring instability, unwanted side reactions, and the environmental concerns associated with corrosive acidic catalysts. The epoxidation was carried out via an in situ performic acid pathway generated from hydrogen peroxide and formic acid under controlled operating conditions. The effects of temperature and reactant molar ratios were systematically evaluated based on oxirane oxygen content (OOC) and relative conversion to oxirane (RCO). An optimal condition was identified at 75°C with a formic acid‐to‐oil molar ratio of 1:1 and a hydrogen peroxide‐to‐oil molar ratio of 1:1, achieving improved oxirane formation as reflected by higher RCO values. Kinetic modeling further demonstrated good agreement between simulated and experimental data, indicating a well‐described reaction pathway under the proposed system. The incorporation of choline chloride provides an alternative strategy for regulating peracid reactivity and improving epoxidation performance of hybrid bio‐based oils.