Production of n-butyl stearate over PA/NaY catalyst

In the present study, the possibility of using PA/NaY (PA = 1-hydroxyethylidenediphosphonic acid) in the esterification reaction of n-butyl acetate production has been investigated. The process optimization using response surface methodology (RSM) was performed and the interactions between the operational variables were elucidated. The optimum values for maximum conversion ratio of stearic acid could be obtained by using a Box-Behnken center-united design with a minimum of experimental work, and the conversion ratio reached 88.0 +/- 0.8% with the molar ratio of alcohol to stearic acid being 4:1 and 1.5 g of PA/NaY catalyst at 125 degrees C for 2 h. Moreover, kinetic models for the esterification reaction catalyzed by PA/NaY were established, and the results were found that the PH mechanism was better at describing the kinetics of this esterification than the LH mechanism. By fitting the kinetic model with the experimental results, it was found that the reaction order n = 2, activation energy of the positive reaction Ea(+) = 34.18 kJ/mol and that of the reverse reaction Ea(-) = 57.70 kJ/mol. (C) 2011 Elsevier B.V. All rights reserved.