Kinetics of nopyl acetate synthesis by homogeneously catalyzed esterification of acetic acid with nopol/Cinetica de la sintesis de acetato de nopilo mediante esterificacion de acido acetico con nopol homogeneamente catalizada

• Published in: Revista Facultad de Ingeniería no. 89; p. 16
• Main Authors: Hurtado-Burbano, Eliana Paola, Villa-Holguin, Aida Luz
• Format: Journal Article
• Language: Spanish
• Published: Universidad de Antioquia, Facultad de Ingenieria 01-12-2018
• ISSN: 0120-6230
• DOI: 10.17533/udea.redin.n89a03

The esterification of nopol with acetic acid to produce nopyl acetate using sulfuric acid as homogeneous catalyst was studied. The reactions were carried out in a batch reactor, at different temperatures (50, 60, 70 and 80 [degrees]C), catalyst concentrations (0.0184, 0.0275, 0.0367 and 0.0480 mol[L.sup.-1] and molar ratio of acetic acid to nopol (1: 1, 1:2, 1:3 and 1: 4); the chemical equilibrium composition was measured at those reaction conditions. It was found that the equilibrium composition is a weak function of temperature, equilibrium conversion was 63, 68, 71 and 75% at 50, 60, 70 and 80[degrees]C, respectively. The reaction was described with a simple power-law model with a second-order kinetic model for both the forward and the backward reaction, using concentration and activities which were predicted by the Universal Functional group Contribution (UNIFAC) method for considering non-ideal behavior of the liquid phase. The forward reaction rate and the equilibrium constants increased with temperature; the relation of the pre-exponential factor with the catalyst amount was evaluated. The activation energy and pre-exponential factor estimated for the forward reaction using the kinetic model based on concentration, were respectively, 28.08 kJ[mol.sup.-1] and 11126 L[mol.sup.-1][h.sup.-1] with a concentration of catalyst of 0.0275 M. Using the kinetic model based on activities, the forward reaction rate constant was 28.56 kJ[mol.sup.-1] and the kfoact was 33860 L[mol.sup.-1][h.sup.-1]. The enthalpy (34.90 kJ[mol.sup.-1]) and the entropy (0.12 kJ[mol.sup.-1] [K.sup.-1]) of reaction were determined using van't Hoff equation.