Experimental and numerical investigation of in situ hydrogen generation via reverse methane combustion: Comparative analysis using CMG and COMSOL“

Abstract

This study investigates reverse methane combustion for in situ hydrogen generation (ISHG) in porous media utilizing a novel combination of experimental and numerical approaches. Two distinct experimental tests were conducted to explore the feasibility and optimization of ISHG. Test 1 focused on validating combustion kinetics using temperature profiles. The experiment confirmed that no hydrogen was produced due to the absence of water and catalyst, with methane almost fully consumed in combustion, while CMG and COMSOL simulations accurately replicated temperature profiles, validating the reliability of numerical models for ISHG. Test 2 represented the final stage of optimization, incorporating a water-soluble catalyst to introduce both water and catalytic activity into the system. While catalyst presence improved reaction conditions, the most significant impact on hydrogen yield was observed during the transition from in situ combustion (ISC) to steam methane reforming (SMR), triggered by the termination of air injection. This transition created a favorable reaction environment, significantly enhancing hydrogen production. The study validates ISHG feasibility and underscores the critical role of water supply, side reactions, and spatial heterogeneity in optimizing hydrogen yield during ISHG, and the need for further model refinement to match real-world conditions. The findings provide foundational insights for advancing ISHG as a scalable, low-carbon hydrogen production method, supporting future decarbonisation efforts.