Low-emission hydrogen production via the thermo-catalytic decomposition of methane for the decarbonisation of iron ore mines in Western Australia

Abstract

The Pilbara, located in Western Australia is one of the largest iron ore-mining regions in the world and will need to achieve significant emission reductions in the short term to conserve the limited carbon budget and abide by the Paris Agreement targets. Green hydrogen has been communicated as the desired solution, however, the high production cost limits the deployment of these systems. The thermo-catalytic methane decomposition (TCMD) process is an alternative solution, which could be implemented as a bridge technology to produce low-emission hydrogen at a potentially lower cost. This is especially attractive for iron ore mines due to the utilisation of iron ore as a process catalyst, which reduces the catalyst turnover costs and can increase the grade of spent iron ore catalyst. In this study, a preliminary techno-economic assessment was carried out in comparison with green hydrogen to determine the feasibility of the TCMD process for the decarbonisation of iron ore mine sites in the Pilbara. The results show that the TCMD process had a CO2 abatement cost between 25 and 40% less than green hydrogen, however, the magnitude of these costs was lowest for mining operations >60 Mt/yr at approximately $150 and $200 USD/t CO2 respectively. Since green hydrogen is expected to have significant cost reductions in the future, integrating renewables already into the mine could reduce emissions in the short term, which could then be extended for green hydrogen production once it becomes viable. The TCMD process, therefore, only has a narrow window of opportunity, although considering the uncertainty of the process and that green hydrogen is a proven technology with greater emission-reduction potential, green hydrogen may be the most suitable solution despite the model results presented in this work.