An iron ore-based catalyst for producing hydrogen and metallurgical carbon via catalytic methane pyrolysis for decarbonisation of the steel industry

• Published in: International journal of hydrogen energy 2023-07, Vol.48 (57), p.21765-21777
• Main Authors: Dawkins, Mickella, Saal, David, Marco, José F., Reynolds, James, Dann, Sandra
• Format: Article
• Language: English
• Subjects: Catalytic methane pyrolysis; High energy ball milling; Hydrogen enriched natural gas; Iron ore; Iron oxide phases
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2023.03.022

Experiments to investigate the catalytic pyrolysis of methane using an iron ore-based catalyst were carried out to optimize catalytic activity and examine the purity of the carbon produced from the process for the first time. Ball milling of the iron ore at 300 rpm for varying times – from 30 to 330 min – was studied to determine the effect of milling time on methane conversion. Optimal milling for 270 min led to a five-fold increase in methane conversion from ca. 1%–5%. Further grinding resulted in a decline of methane conversion to 4% shown by SEM to correspond to an increase in particle size caused by agglomeration. Data from Raman and Mössbauer spectroscopy and H2 temperature programmed reduction indicated a change in phase from magnetite to maghemite and hematite (at the particle surface) as the grinding time increased. Analysis of the carbon produced as a byproduct of the reaction indicated a highly pure material with the potential to be used as an additive for steel production. •CMP, a transitional technology for decarbonising steel making has been explored.•Magnetite ore was a cost-effective, efficient catalyst for the process.•Optimisation of the surface area of raw iron ore increases catalytic activity.•Carbon by-product from the reaction had comparable structure to metallurgical coke.