Periodic reactor operation for parameter estimation in catalytic heterogeneous kinetics. Case study for ethylene adsorption on Ni/Al2O3

Periodic operation of chemical reactors has usually been analyzed for a potential gain in performance. However, at the laboratory scale, periodic operation of a catalytic reactor can be used for kinetic studies with better parameter estimation, which is inherent to transient kinetic studies. Different mathematical methods are developed and compared in this study to simulate and model concentration cycling in a fixed bed catalytic reactor. Different cases including dissociative and molecular adsorption are considered with or without external and internal mass transfer limitations. The analysis of these cases gives information on the contribution of the different parameters on the phase lag and gain loss. This information can be used to better plan experimental kinetic studies. Ethylene adsorption over a Ni/Al2O3 catalyst has been studied experimentally in a dedicated set-up with a high-speed Infrared analyzer capable of analyzing the outlet gas mixture with a data acquisition frequency up to 30 Hz. The data are modeled with one of the analytical expressions developed in this work to estimate the equilibrium adsorption constant. (C) 2018 Elsevier Ltd. All rights reserved.