Transportation and mobility tasks in mining operations bear the bulk of the industry’s environmental costs regarding carbon dioxide (CO2) gas emissions. Bulky haulers weighing hundreds of tons consume hundreds of liters of diesel every hour. But this presents a significant opportunity to mining companies: if they can replace transportation and mobility fleets with vehicles powered by green hydrogen, they can drastically reduce their emissions.
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What is Green Hydrogen?
Hydrogen is a fuel material and an industrial feedstock that does not emit CO2 when burned. But it is made in energy-intensive processes that can significantly counteract the environmental benefits of emission-free combustion. Green hydrogen is produced using energy from renewable sources.
Just like carbon (C), hydrogen (H) can ignite and burn to release energy, interacting with the atmosphere’s oxygen (O2) as it does so. Unlike carbon, which reacts with oxygen to make carbon dioxide (CO2) when it burns, hydrogen and oxygen only make water (H2O).
While the amount of energy released burning hydrogen is comparable to the amount released burning carbon, the main emission is much less harmful. Burning hydrogen only emits water vapor molecules rather than CO2. In the atmosphere, other elements involved in the hydrogen-oxygen reaction lead to a small release of nitrogen oxide.
Natural hydrogen (H2) rarely occurs in nature, so hydrogen fuels must be produced. This is usually carried out via steam methane reforming (SMR).
SMR extracts usable hydrogen from natural gas or methane (CH4) by heating it with extremely hot water vapor (steam) and typically a catalyst material. This separates the carbon from hydrogen atoms in methane to produce carbon monoxide and hydrogen.
SMR creates carbon dioxide emissions, consumes a finite resource (methane), and requires large amounts of water and energy.
Green hydrogen – which currently represents only a fraction of hydrogen production worldwide – uses water electrolysis to extract hydrogen from water (H2O). In electrolysis, water is split into its constituent hydrogen and oxygen parts when a large current of electricity flows through it.
Water electrolysis is not a very efficient means of transporting energy: more energy is needed in electricity than can be captured again in hydrogen fuel. However, if all of the energy required for water electrolysis is met from renewable sources such as solar and wind, then the emission-free fuel it produces will also be renewable – this is green hydrogen.
Green hydrogen accounts for less than one percent of the world’s annual hydrogen fuel production, which the International Energy Agency (IEA) recently reported will need to increase from 87 million tons (of mostly SMR-produced hydrogen) to 306 million tons (of green hydrogen) by 2050 for the world to meet emissions targets
This will require significant investment, where the mining industry could play a crucial role.
Mining Can Create Demand for Green Hydrogen, Spurring Infrastructure Investment
Mining (and other heavy industries, such as construction and shipping) is a single large user of fossil fuels and a large emitter of carbon dioxide. This is due to demands from mobility and transportation; haulage trucks moving material around mine sites use huge amounts of fuel.
This presents complimenting opportunities: if the mining sector switches to green hydrogen for its fuel needs, it will eliminate carbon dioxide emissions while providing an impetus for investment into green hydrogen infrastructure.
In a recent industry report, market analysts predict that mining companies will begin to produce green hydrogen with investments in on-site hydrogen infrastructure and renewable energy capture wrapped up in the outlay costs for a new mining venture.
The report notes that the localized cost of electricity (LCoE) from renewable sources is trending downward globally. The cost of green hydrogen will also continue to decrease as the electricity bill represents up to three-quarters of the total production costs for green hydrogen.
Analysts said green hydrogen would likely be a significant factor in decarbonizing the mining sector in the coming decades.
First Green Hydrogen Trucks in Mining
There is already movement within the mining sector toward green hydrogen. A platinum mine in Limpopo, South Africa, recently started using hydrogen-powered haulage trucks.
The mine operator intends to use green hydrogen for these vehicles, but the hydrogen power infrastructure in South Africa is still relatively sparse.
Working with private partners, the South African government is creating a “hydrogen valley” in the nation’s platinum belt, focused primarily on producing green hydrogen.
The Limpopo mine’s operator is involved in this plan, and its investment in hydrogen-powered haulage trucks means it will be one of the first beneficiaries of a robust local infrastructure.
The mine contributes 140 MW of energy captured with photovoltaics and will also house hydrogen production and storage facilities.
As well as powering the platinum mine’s trucks, the green hydrogen produced at Limpopo will also be available for local energy needs, decarbonizing transport and mobility across the region.
Read more: How Do Photovoltaics Power Mines?
References and Further Reading
Collins, L. (2021). A net-zero world 'would require 306 million tonnes of green hydrogen per year by 2050': IEA. [Online] Recharge. Available at: https://www.rechargenews.com/energy-transition/a-net-zero-world-would-require-306-million-tonnes-of-green-hydrogen-per-year-by-2050-iea/2-1-1011920 (Accessed on 16 August 2022).
Green hydrogen key to decarbonising mining – report. (2021) [Online] Mining.com. Available at: https://www.mining.com/green-hydrogen-key-to-decarbonising-mining-report/ (Accessed on 16 August 2022).
Howarth, R.W., and M.Z. Jacobson (2021). How green is blue hydrogen? Energy Science and Engineering. doi.org/10.1002/ese3.956.
Pilkington, B. How is Green Hydrogen Produced? [Online] AZO Cleantech. Available at: https://www.azocleantech.com/article.aspx?ArticleID=1523 (Accessed on 16 August 2022).
Pilkington, B. What is the Difference Between Green Hydrogen and Blue Hydrogen? [Online] AZO Cleantech. Available at: https://www.azocleantech.com/article.aspx?ArticleID=1525 (Accessed on 16 August 2022).
Preyser, J. (2021). Miners experiment with hydrogen to power giant trucks. [Online] BBC News. Available at: https://www.bbc.co.uk/news/business-59576867 (Accessed on 16 August 2022).