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°C), catalyst concentrations (0.0184, 0.0275, 0.0367 and 0.0480 molL −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°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 kJmol −1 and 11126 Lmol −1 h −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 kJmol −1 and the k f o,act was 33860 Lmol −1 h −1. The enthalpy (34.90 kJmol −1) and the entropy (0.12 kJmol −1 K −1) of reaction were determined using van't Hoff equation. RESUMEN: Se estudió la esterificación de nopol con ácido acético para producir acetato de nopilo utilizando ácido sulfúrico como catalizador homogéneo. Los experimentos se llevaron a cabo en un reactor por lotes variando la temperatura (50, 60, 70 y 80°C), la concentración del catalizador (0.0184, 0.0275, 0.0367 y 0.0480 molL −1) y la relación molar de ácido acético a nopol (1: 1, 1:2, 1:3 y 1: 4); la composición del equilibrio químico se midió a las condiciones de reacción. La conversión de equilibrio fue 63, 68, 71 y 75% a 50, 60, 70 y 80°C, respectivamente. La reacción se describió con un modelo de potencia simple con un modelo de segundo orden en ambas direcciones, usando concentraciones y actividades, las cuales se predijeron con el método de contribución de grupos UNIFAC. Se determinaron las constantes de velocidad de la reacción directa y la constante de equilibrio, las cuales aumentaron con la temperatura; se evaluó la relación del factor pre-exponencial con la cantidad de catalizador. La energía de activación y el factor pre-exponencial estimados para la reacción hacia adelante usando el modelo basado en concentración fueron respectivamente 18.08 kJmol −1 y 11126 Lmol −1 h −1 con una concentración de catalizador de 0.0275 M. Usando el modelo basado en actividades la constante de velocidad directa fue 28.56 kJmol −1 y el factor pre-exponencial 33860 Lmol −1 h −1. La entalpía (34.90 kJmol −1) y la entropía (0.12 kJmol −1 K −1) de reacción se determinar...
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