Esterification of Methacrylic Acid with Methanol: Process Optimization, Kinetic Modeling, and Reactive Distillation

The esterification of methacrylic acid with methanol catalyzed by NKC-9 resin (a cation-exchange resin with sulfonate groups) was conducted in a stainless stirred batch reactor. The effects of catalyst loading, initial molar ratio of reactants, temperature, and pressure on this esterification reaction were investigated. A kinetic model based on the Langmuir–Hinshelwood mechanism was developed in which methacrylic acid and methanol were considered to be uniformly adsorbed on the surface of catalysts. Model parameters, including reaction equilibrium constants, activation energy, enthalpy change, entropy change, and rate constants, were solved. The accuracy of the model was validated by means of both experimental proofs and standard deviation between the predicted and experimental data. Finally, the reactive distillation process was proposed for continuous synthesis and separation of methyl methacrylate.