Continuous synthesis of oleyl oleate in supercritical carbon dioxide using solid p-toluenesulfonic acid as catalyst

Supercritical carbon dioxide (SC-CO2) was used as solvent to synthesize oleyl oleate as an analog of Jojoba oil from oleic acid and oleyl alcohol with high conversion (100%) of the acid into ester in a short time of 100 min. Utilizing a low cost solid catalyst, p-toluenesulfonic acid monohydrate (PTSA), the esterification reaction was performed, without any prior preparation step, in a flow mode, at a pressure of 147 bar and a temperature of 60 degreesC. This method seems industrially suitable for the production of oleyl oleate. The solubility of a mixture of oleyl alcohol and oleic acid in SC-CO2 were also measured to calculate the alcohol to acid ratio and the esterification yield.