Kinetic Study of Catalytic Surface Reaction in Methane Pyrolysis in Molten Metal Bubble Column Reactors

Abstract

Hydrogen can be produced via methane pyrolysis in a molten metal bubble column to create separable carbon. Tin is used as a base metal in this study, and catalytically active metals such as nickel and copper are added to it. The study uses a differential equation that takes into account both parallel catalytic surface reactions on the bubble surface and conventional noncatalytic reactions in the gas bulk. The research analyzes the effect of molten metal type, temperature, and orifice diameter on the bubble surface-to-volume ratio and their effects on the catalytic surface reaction and the gas phase reaction in the bubble. The results indicate that the 5 wt% Ni-Sn mixture performs best among the studied alloys, with a calculated surface reaction fraction of approximately 90% at 950 _C, confirming the dominant effect of catalytic activity. In addition, the study estimates the conversion under different conditions of temperature, orifice diameter, and molten metal height by solving the differential equation using kinetic parameters derived from experimental results. The results can be used for future reactor design.