Thermal Methane Cracking on Molten Metal: Kinetics Modeling for Pilot Reactor Design

Up to 80% of hydrogen production is currently carried out through CO2 emission-intensive natural gas reforming and coal gasification. Water-splitting electrolysis using renewable energy (green H-2) is the only process that does not emit greenhouses gases, but it is a quite energy-demanding process. To significantly contribute to the clean energy transition, it is critical that low-carbon hydrogen production routes that can replace current production methods and can expand production capacity to meet new demands are developed. A new path, alternative to steam reforming coupled with CCS (blue H-2) that is based on methane cracking, in which H-2 production is associated with solid carbon instead of CO2 (turquoise H-2), has received increasing attention recent years. The reaction takes place inside the liquid bath, a molten metal reactor. The aim of this article is to model the main kinetic mechanisms involved in the methane cracking reaction with molten metals. The model developed was validated using experimental data produced by the University of La Sapienza. Finally, such a model was used to scale up the reactor architecture.

Automated summary

Currently, the majority of hydrogen production relies on CO2 emission-intensive methods such as natural gas reforming and coal gasification. Water-splitting electrolysis using renewable energy is a cleaner alternative, but it requires significant energy input. To promote the clean energy transition, it is crucial to develop low-carbon hydrogen production routes that can replace current methods and meet increasing demands. The utilization of methane cracking as an alternative to steam reforming coupled with CCS has gained attention. This article presents a model for the kinetic mechanisms involved in methane cracking with molten metals, validated using experimental data and used for reactor scaling.