Mechanism and kinetics of the CoCl2‐catalyzed esterification reaction of castor oil with oleic acid

Abstract

AbstractThe apparent orders of the Lewis acid‐catalyzed esterification reactions between castor oil and oleic acid are known to change with the catalyst used and with the reaction temperature. A mechanism is proposed in this study to explain the variations (with temperature) in the apparent orders of the cobalt chloride‐catalyzed esterification reaction between castor oil and oleic acid. According to the proposed mechanism, an acid‐catalyst intermediate forms in an initial, fast quasi‐equilibrium step, and this intermediate then reacts with the oil to yield the products and to regenerate the catalyst in the rate‐determining second step. A general rate expression, with an acid concentration term and a temperature‐dependent constant in the denominator, is derived from the proposed mechanism and is verified with data obtained at different temperatures.