No abstract

The heterogeneous esterification reaction of acrylic acid with hexanol over three different cation-exchange resins, Amberlyst 131, Amberlyst 15, and Dowex 50Wx-400, was investigated. Surface area, pore volume, average pore diameter, and acid capacity analyses were carried out for these three catalysts. Amberlyst 131 gave the highest conversion, and therefore, further experiments were performed catalyzed by Amberlyst 131. The absence of external and internal mass transfer resistances was investigated for the esterification of acrylic acid with hexanol. Experiments showed that the reaction is controlled by chemical step rather than external and internal mass transfer steps. The effects of temperature, catalyst loading, and alcohol to acid molar ratio on the conversion of acrylic acid were determined. The activation energy and kinetic and adsorption constants were determined according to the LangmuirHinshelwood-Hougen-Watson mechanism. C

The esterification reaction of acrylic acid with isobutyl alcohol in the presence of ion exchange resins, Amberlyst 15, Amberlyst 131, and Dowex 50wX-400, has been studied. According to experimental results, Amberlyst 131 was a more effective catalyst compared with the other ion exchange resins. The effects of catalyst loading, stirrer speed, initial alcohol to acid molar ratio, and temperature on the conversion of acrylic acid were investigated. The experimental data were tested by using Pseudohomogeneous, Eley−Rideal and Langmuir−Hinshelwood−Haugen−Watson models. The nonideality of the reaction medium was taken into account by using activities instead of concentrations. The activity coefficients were calculated using the UNIQUAC group contribution method. The activation energy and kinetic and adsorption constants were determined according to the model representing the dual site adsorption, which comprises the data with minimum error.