Esterification Reaction Kinetics of Acetic and Oleic Acids with Ethanol in the Presence of Amberlyst 15

Abstract

Esterification of acetic and oleic acids with ethanol in the presence of Amberlyst 15 was evaluated as a function of reaction temperature, fatty acid-to-ethanol molar ratio, catalyst concentration, and fatty acid carbon chain length. All reactions were carried out using a batch reaction system, and the resulting experimental data was modeled using Langmuir–Hinshelwood–Hougen–Watson and Eley–Rideal surface reaction kinetic models to determine reaction rates. Esterification of acetic and oleic acid with ethanol increases with increasing reaction temperature, catalyst concentration, and fatty acid-to-alcohol molar ratio. Shorter carbon chain lengths also enhanced esterification. A maximum esterification of 67.1 and 41.6% was observed for acetic and oleic acid, respectively. Esterification of both fatty acids with ethanol in the presence of Amberlyst 15 was determined to be a surface reaction limited. The reaction rate constant (k) for acetic acid esterification was determined to be 4.31/min according to the ER model ( $$R^2 \ge 0.94$$ ), while oleic acid esterification was determined to be 0.263/min ( $$R^{2} \ge 0.79$$ ) based upon the LHHW model.