On the Mechanism of Methane Conversion in the Non\u0441atalytic Processes of Its Thermal Pyrolysis and Steam and Carbon Dioxide Reforming

E. Busillo,V. I. Savchenko,V. S. Arutyunov

doi:10.1134/s0965544121110037

Abstract

A detailed kinetic modeling of the noncatalytic processes of thermal pyrolysis\t\t\t\t\tand steam and carbon dioxide reforming of methane revealed almost completely\t\t\t\t\tidentical kinetics of the methane conversion in these processes. This suggests\t\t\t\t\tthat, in the temperature range 1400–1800 K, the initial stage of conversion of\t\t\t\t\tmethane in all these processes is its thermal pyrolysis. The modeling results\t\t\t\t\tagree well with the experimental data on methane pyrolysis. For the temperature\t\t\t\t\trange examined, the Arrhenius expressions (pre-exponential factors and\t\t\t\t\tactivation energy) were obtained in the first-order kinetics approximation for\t\t\t\t\tthe rate of methane conversion in the processes studied. The expressions derived\t\t\t\t\tmay be useful for making preliminary estimates and carrying out engineering\t\t\t\t\tcalculations.

Highlights

In recent years, the kinetics and thermodynamics of the catalytic processes of steam and carbon dioxide reforming of methane have become the focus of numerous studies
We carried out the kinetic analysis of steam reforming [14] and carbon dioxide reforming [15] of methane and showed that, in both cases, the methane conversion and hydrogen formation began at a much earlier point of time than the conversion of Н2О and СО2, respectively (Fig. 1)
[14, 15], we made an assumption that steam reforming and carbon dioxide reforming of methane proceed via its preliminary thermal pyrolysis to acetylene, which conclusion was further extended to incorporate higher homologs of methane [15, 20]

Summary

Introduction

The kinetics and thermodynamics of the catalytic processes of steam and carbon dioxide reforming of methane have become the focus of numerous studies (see, e.g., [12, 13]). To obtain the Arrhenius expressions for the rate of methane conversion in each of the processes considered, detailed calculation of the process kinetics at each specific temperature was performed in order to select the expression most adequately describing the methane conversion.

Results

Conclusion