Reaction Kinetics and Thermodynamic Equilibrium for Butyl Acrylate Synthesis from n-Butanol and Acrylic Acid

The esterification reaction of n-butanol with acrylic acid in the presence of a commercial ion-exchange resin, Amberlyst 15-wet, was carried out in a batch reactor. The reactions were performed at different temperatures (50 to 90 degrees C), different n-butanol/acrylic acid molar ratios (2 and 3), and different catalyst amounts (1 wt % to 3.5 wt %). Different reaction rate expressions were evaluated. A simplified Langmuir-Hinshelwood-Hougen Watson kinetic model was found to be the best model to describe the experimental results. This model is given by the following expression: r = K-c center dot((a(1)center dot a(2) - (a(3)center dot a(4))/K-eq)/(1 + K-4 center dot a(4))(2)), with k(c) (mol.g(cat)(-1).min(-1)) = 1.52 X 10(7) - 66 988/(RT) and K-4 = 1.589. Also equilibrium experiments were carried out. The proposed equilibrium equation was K-eg = exp((-(1490 +/- 577)/T + (7.21 +/- 1.67)). From this equation, it was possible to determine the reaction standard enthalpy and entropy values: Delta H degrees = 12.39 +/- 4.80 [kJ/mol] and Delta S degrees = 59.98 +/- 13.87 [J/mol.K].