Liquid-phase esterification of methacrylic acid with methanol catalyzed by cation-exchange resin in a fixed bed reactor: Experimental and kinetic studies

The kinetic behavior of esterification between methacrylic acid and methanol catalyzed by NKC-9 resin was studied in a fixed bed reactor. The reaction was conducted in the temperature range of 323.15 to 368.15 K with the molar ratio of reactants from 0.8 to 1.4 under certain pressure. The measurement data were regression with the pseudo-homogeneous (P-H), Eley-Rideal (E-R), and Langmuir-Hinshelwood (L-H) heterogeneous kinetic models. Independent adsorption experiments were implemented to gain the adsorption equilibrium constants of four components. Among the above three models, the L-H model exhibited the best fitting results. The stability of NKC-9 was evaluated by long-term running with the yield of methyl methacrylate no decrease during 3000 h operation. The structure and physicochemical properties of the new and used catalyst were performed by several characterizations including thermogravimetric analysis (TG), scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) and so on.