A kinetic study on the methanol conversion to dimethyl ether over H-ZSM-5 zeolite

The intrinsic kinetics of the methanol dehydration to dimethyl ether (DME) over commercial ZSM-5 zeolite is studied both theoretically and experimentally to establish the rate equation of the process. A set of kinetic models based on Langmuir-Hinshelwood (L-H) and Eley-Rideal (E-R) formalism is proposed for the methanol conversion to DME. The experimental verification of the developed models reveals an essential correspondence between the L-H kinetics and the experimental data. In contrast, E-R models provide an insufficient description of the methanol dehydration kinetics. In the frame of L-H formalism, it is shown that both, the associative and dissociative, mechanisms of the methanol dehydration are acceptable in the experimental scenario studied. The discrimination of the established models to choose the most realistic one is performed by comparing the estimated activation energies and adsorption enthalpies with the literature data.