Enzymatic kinetics of cetyl palmitate synthesis in a solvent-free system

Cetyl palmitate was synthetized by esterification the cetyl alcohol with palmitic acid in a solvent-free system. Reactions were performed in batch mode using commercial lipase Lipozyme RM IM as catalyst. Stirring speed (180, 480 and 720 rpm), temperature (60, 70, 80 and 87 °C), amount of catalyst (0.5, 1.0 and 1.5% wt% related to the mass of substrates) and alcohol:acid molar ratio (0.5:1, 1:1 and 2:1) were evaluated and best reaction conditions obtained were 480 rpm, 70 °C, 1.0% of enzyme and 1:1 M ratio. A novel kinetic model based on random-sequential bi-bi mechanism was proposed and showed a good agreement with experimental data. Furthermore, this model was proved to be suitable for kinetics predictions with a small uncertainty. The catalyst was recycled and showed good stability since reaction conversion decreased only 6.8% after 15 reuses.