КІНЕТИЧНІ ДОСЛІДЖЕННЯ ТА МОДЕЛЮВАННЯ ПРОЦЕСУ ЕСТЕРИФІКАЦІЇ БЕНЗОЙНОЇ КИСЛОТИ

Abstract

The kinetic regularities of benzoic acid esterification with 1-butyl alcohol catalyzed by p-toluenesulfonic acid under stationary conditions have been studied. The study shows that the reaction has the first order with respect to benzoic acid. It is proposed a method for calculating the forward and reverse reaction constants, and the equilibrium constant using the determined effective rate constant of the esterification reaction. The preexponential factors and activation energies of the forward and reverse reactions as well as the thermal effect and the entropy change of the esterification reaction have been calculated. In particular, the thermal effect of benzoic acid esterification reaction with 1-butyl alcohol at a temperature of 365.2–389.4 K is 622 J∙mol-1, and the activation energies of the forward and reverse reactions are 58.40 and 57.70 kJ∙mol-1, respectively. The calculated kinetic characteristics of the esterification reaction were used in mathematical modeling of the butyl benzoate obtaining process under nonstationary conditions. Taking into account the kinetic characteristics of the reactions and the stages peculiarities of the butyl benzoate obtaining process the calculation of the change in the benzoic acid conversion over time was performed. The study shows that under optimal conditions the benzoic acid conversion in 120 min reaches 92 %. The use of the experimental results and the created mathematical model of benzoic acid esterification process with 1-butyl alcohol makes it possible to calculate of kinetic curves of the reagent consumption under nonstationary conditions. The experimentals can be used to improve the technological process of the butyl benzoate manufacture in the industry.