Kinetic Modeling of Oxidative Coupling of Methane Over Mn/Na2WO4/TiO2 Catalysts

In this work, the kinetic of oxidative coupling of methane reactions using Mn/Na2WO4/TiO2 as a catalyst has been modeled. The process of the oxidative coupling of methane consists of complicated interactions between transport phenomena and chemical kinetics. Simulation and modeling have been conducted considering the details of the reaction and the kinetics of the process of the oxidative coupling of methane on laboratory scale. Kinetic experiments were designed and conducted in a catatest setup which was equipped to a differential fixed-bed reactor. In addition, more than 24 experiments were done under different operational conditions, namely at temperatures between 923-1223 K, at atmospheric pressure, at methane to oxygen ratios of 1, 2, 3, 4.5, and at GHSV’s of 8000, 10000, 14000, and 18000 h-1. The results of each experiment in terms of the amount of selectivity of hydrocarbon products (ethylene and ethane) and carbon oxide products (carbon dioxide and carbon monoxide), the methane conversion, and the efficiency of desired hydrocarbon products were assessed. The validation of the method by a comparison between the experimental data and the kinetic model outputs was also performed. Good agreement between these data declares that the kinetic model in the range of our operational conditions is valid. MATLAB was used in order to model the kinetics of the reaction. In this model, all the equations of conservation of mass were solved for all the components of the system. To optimize the model, the sensitivity analysis was also carried out. Finally, the outcomes of model were compared with the experimental results and the kinetic constants and activation energies were calculated for the reactions.