Kinetics study on esterification of acrylic acid and ethanol over acidic cation-exchange resin beads Amberlyst 35

The heterogeneous kinetics and adsorption behavior for the esterification of acrylic acid and ethanol were studied by using a fixed-bed reactor over an acidic cation-exchange resin beads, Amberlyst 35. The reaction experiments were conducted at 318.15 K–348.15 K under atmospheric pressure. The influences of molar ratios of ethanol to acrylic acid in the feed (θBo) and the mass transfer resistances on the kinetic behavior were also investigated. The experimental results show that the equilibrium conversion of acrylic acid increases with increasing reaction temperature and θBo. Moreover, the adsorption experiments were also made to determine the relative adsorption strengths among the reacting species. The results reveal that the magnitude of adsorption strengths obeyed the sequence of water > acrylic acid > ethanol > ethyl acrylate. The kinetic data obtained from the present study were correlated with the ideal-quasi-homogeneous (IQH), the non-ideal-quasi-homogeneous (NIQH), the Langmuir-Hinshelwood-Hougen-Waston (LHHW), the Eley-Rideal (ER) models, the modified LHHW (M-LHHW) and the modified ER (M-ER). The best-fitted values of the kinetic parameters were reported. The correlated results indicated that the M-LHHW model provides the best representation for this reaction system.