Epoxidation of jatropha oil using heterogeneous catalysts suitable for the Prileschajew reaction: Acidic resins and immobilized lipase

Sulphonated polystyrene resins, Nafion-silica and immobilized lipase were used as heterogeneous catalysts for the epoxidation of jatropha oil. Immobilized lipase showed ca. 100% conversion and 100% epoxide selectivity at 24 h. However, this catalyst cannot be reused because it completely deactivates after one use. For the selective epoxidation of vegetable oils with percarboxylic acids the most crucial feature to prevent the formation of glycols is to minimize the exposure of the epoxide to the acidic sites of the catalyst. This can be achieved using resins with a high level of cross-linking and with low external surface area. Activity can be increased by increasing the strength of the acid sites. Amberlite IR-120 was the best heterogeneous catalysts, yielding ca. 90% conversion and 70% epoxide selectivity, both stable through five re-uses. Dowex 50WX2 afforded the production of glycols with more than 90% selectivity at conversions of ca. 90%.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (31 K)Download as PowerPoint slideResearch highlights▶ Amberlite IR-120 was the best catalyst, yielding 70% epoxide selectivity. ▶ Amberlite IR-120 was stable through five re-uses. ▶ Low-accessible acid sites increase epoxide selectivity. ▶ Highly accessible acid sites increase glycol selectivity. ▶ Epoxidation rate is favored by acid strength.