Correction of Methane Oxidation Kinetic Parameters in On-site Hydrogen Production Based on Combustion Tube Experiments

In numerical simulation studies of methane oxidation, significant errors in simulation results can arise due to the uncertainty of reaction kinetics parameters. Therefore, this study aims to investigate the exothermic behavior of natural gas (primarily methane) oxidation in reservoir environments when injected with hot air (mainly oxygen). The study incorporates experimental data from combustion tube experiments to adjust the kinetic parameters, such as the pre-exponential factor, used in the numerical simulation. By combining experimental and numerical approaches, it is discovered that the significant errors in numerical simulation are primarily caused by the orders of magnitude difference in the pre-exponential factor between the actual experiments and the numerical simulation. Both excessively high and low pre-exponential factors can result in significant errors in chemical reaction rates. After experimental adjustments, the determined pre-exponential factor is 1.09E8, resulting in a 2.7% error in the methane oxidation kinetic model. Furthermore, the study confirms through dual verification of experimental and numerical simulation that the methane oxidation temperature can reach up to 450 ℃. This research not only improves the accuracy of methane oxidation kinetics simulation but also helps deepen the understanding of methane oxidation behavior and mechanisms. It holds significant theoretical and practical implications for optimizing in-situ hydrogen production from natural gas.