Western Australia’s Magnetite Could Hold Vast Natural Hydrogen Reserves

The hunt is under way for naturally occurring hydrogen sources that might help accelerate the shift towards a low-carbon energy future. Hydrogen is an exceptionally clean fuel, yet most of today’s supply is still made from fossil fuels.

Accessing plentiful underground hydrogen reserves would address that issue. Several geological mechanisms can produce the gas, including the reaction that occurs when hot water comes into contact with magnetite, a mineral found in iron ore.

Western Australia has extensive iron ore deposits beneath its surface. Researchers led by Edith Cowan University in Australia set out to examine how much hydrogen gas may already be present in these formations and how much could be generated over time.

Published in the International Journal of Hydrogen Energy, their study delivers encouraging results and improves scientists’ understanding of the geological conditions that determine the volume of hydrogen magnetite can produce.

"Australia could be sitting on a massive, untapped energy reserve - and the potential is enormous," says chemical engineer Alireza Keshavarz, from Edith Cowan University.

"There is enough hydrogen for Australia to benefit for generations, and potentially enough for us to become a major exporter of clean energy to the rest of the world."

Magnetite and natural hydrogen in Western Australia

The team did not drill for hydrogen during this research. Instead, it carried out laboratory tests of the chemical reactions between water and magnetite under high pressure, maintaining a temperature of 200 °C for 60 days.

These conditions partly mimic those found underground. The experiments showed not only that hydrogen gas formed, but also that magnetite powder generated substantially more hydrogen per gram than a magnetite slab: approximately five times more on a gram-for-gram basis.

That result indicates that fractured, porous rocks offering a larger surface area could be the most promising locations for hydrogen gas. It also points to possible ways of increasing hydrogen production.

"Our findings show that hydrogen production depends not only on the amount of magnetite present, but also on how easily water can access fresh mineral surfaces through fractures, pores and permeable pathways," says energy engineer Stefan Iglauer, from Edith Cowan University.

"This work helps bridge the gap between laboratory experiments and real geological systems."

Rock surfaces, hematite and hydrogen generation

The study also produced further findings.

As the reaction generated hydrogen, it converted much of the magnetite left behind into hematite. On a larger scale, this could form a protective barrier that stops additional water from reaching the magnetite.

Earlier experiments have mostly used magnetite powder rather than the slab-shaped samples included in this work. A clearer understanding of the real-world geology involved should therefore make future modelling more precise.

"This comparison and characterization are important for two reasons," write the researchers in their published paper. "First, the hydrogen production data from field-collected slabs directly represent the geological composition and geometry exposed to water in natural settings."

"Second, the interaction between rock surfaces and water during hydrogen generation alters surface characteristics, which has significant implications for rock integrity in gas geo-storage applications."

Many obstacles still need to be overcome in locating, producing and extracting hydrogen gas from iron ore deposits. Nevertheless, the new research marks an important advance in identifying the quantities of hydrogen that magnetite may release and the most efficient methods for producing it.

"If we can unlock this resource at scale, it could be transformative for our energy future," says energy engineer Kaveh Moghanirahimi, from Edith Cowan University.

"We even see the potential for Western Australia to strengthen its energy independence during times of crisis through access to this naturally generated hydrogen."

The research has been published in the International Journal of Hydrogen Energy.

This article was fact-checked and edited by Rebecca Dyer. Although we take pride in our process, we are only human. If you notice an error, please let us know.