Lipase-Catalyzed Synthesis of Cetyl Palmitate in the Presence of n-Hexane and Ethyl Ether

Cetyl palmitate was produced by the esterification of palmitic acid with cetyl alcohol using n‐hexane and ethyl ether as solvents and a commercial lipase as a catalyst. The effect of solvents to reagents mass ratio (0.5 : 1–3 : 1), percentage of n‐hexane in the solvent mixture (0–100%), and reaction temperature (25–55°C) on the reaction rate were evaluated for a fixed amount of enzyme (1 wt% related to the total mass of substrates) in an equimolar mixture of palmitic acid and cetyl alcohol. Temperature and n‐hexane percentage in the solvent had positive effects on the reaction rate. The total solvent‐to‐reagent mass ratio showed a negative effect on the reaction rate when a solvent mixture rich in ethyl ether was used. The higher the concentration of n‐hexane, the lower the effect of the mass ratio of solvents to reagents on the reaction rate. Although the amount of ethyl ether in the solvent mixture had a negative effect on the reaction rate, it had a positive effect on the solubility of the system, that is, the more ethyl ether in the mixture, the lower the solvent to reagents mass ratio required to ensure a homogeneous mixture. A ping‐pong bi‐bi mechanism‐based model was proposed to represent the system kinetics and was well fitted to the experimental data.