Esterification Kinetics of Cyclohexanecarboxylic Acid and Ethylene Glycol in Diesel Oil With or Without a ZnAl-HTlc Catalyst

Abstract

Esterification is an interesting method to decrease the naphthenic acid concentration of highly acidic petroleum, because these acids may cause serious corrosion in oil processing equipment. Taking cyclohexanecarboxylic acid as a model compound of naphthenic acids and performing batch runs at different temperatures, the reaction kinetics of cyclohexanecarboxylic acid esterification with ethylene glycol was investigated by using ZnAl-HTlc as a heterogeneous catalyst and without catalyst. The results demonstrated that esterification kinetics follows a second-order reaction with or without ZnAl-HTlc catalyst. The activation energy, E_a; frequency factor, k₀; and reaction rate constant, k, were also evaluated. ZnAl-HTlc can obviously reduce the reaction activation energy and speed up the reaction. The reaction kinetics model was validated by compared the experimental data with calculated data.