Industrial & Engineering Chemistry Research, Vol.43, No.24, 7697-7701, 2004
Synthesis of octyl palmitate in various supercritical fluids
Octyl palmitate was enzymatically synthesized from palmitic acid and octanol. The synthesis of octyl palmitate was investigated in three supercritical fluids, namely, carbon dioxide, methane, and ethane, using three different enzymes. The effects of temperature, initial water content, alcohol concentration, and enzyme loading on the conversion were determined. Among the enzymes, Novozym 435 (immobilized) catalyzed the reaction, resulting in the highest conversion compared to the other lipases, irrespective of the solvent used. Further, Novozym 435 was active over a wider range of temperatures (35-65degreesC) compared to the other two enzymes. The lowest esterification (76%) was obtained in supercritical carbon dioxide, while the highest esterification was obtained in supercritical methane (85%). The results thus indicate that for this reaction, among the systems investigated, supercritical methane and Novozym 435 are the best supercritical fluid and enzyme, respectively.