Decoding the role of hydrogen in mining

Mahtab Salehii, Global Solution Architect for Sustainability, Mining, Metals & Minerals at
Schneider Electric

Tara Rana, Global Solution Architect for Mining, Metals & Minerals at Schneider Electric
In our efforts to combat climate change and limit global temperature rise to below two
degrees by 2050, it is crucial to explore and evaluate every technology that holds
potential value. Among the various technologies gaining significant attention,
hydrogen (H2) technology stands out. In this article, we will explore the emerging
applications of hydrogen in the mining industry and discuss its role in
decarbonisation efforts.

Hydrogen: an abundant energy carrier with multiple applications in mining
Hydrogen has captured considerable attention for several reasons. Firstly, it is the most
abundant element in the universe, offering a virtually limitless supply. Additionally, hydrogen
exhibits characteristics similar to fossil fuels, allowing it to be stored, transferred, and burned
to produce high-temperature heat. However, unlike natural gas or oil, hydrogen does not
exist naturally in the world but rather serves as an energy carrier that requires production.
Numerous new applications of hydrogen have been proposed across different industries,
including transportation and mining. Let us examine some of the key applications of
hydrogen in the mining sector.

1. Fleet Decarbonisation
   One promising application of hydrogen in mining is fleet decarbonisation, particularly for
   heavy mobile equipment such as haul trucks. Compared to electric trucks, trucks equipped
   with hydrogen fuel cells offer several advantages, including fast charging and extended
   ranges, making them an attractive option.
2. Energy Storage
   Hydrogen can also be used for energy storage purposes. It can store surplus renewable
   electricity and be used later for thermal or electricity generation. At high pressures, hydrogen
   can store up to 40,000 Wh/kg, whereas the best available lithium-ion batteries on the market
   can only store up to 280 Wh/kg.
3. Electricity Generation
   In mining operations, hydrogen can power on-site generation units, meeting the electricity
   demand of the mining operations. By using hydrogen for electricity generation, mines can
   reduce their reliance on traditional fossil fuel sources.
4. Steel and Copper Production
   Hydrogen can serve as a reductant and source of industrial-grade heat, offering a potential
   alternative to fossil fuels in carbon-intensive industries like steel and copper production. By
   replacing fossil fuels with hydrogen, these industries can significantly reduce their carbon
   emissions.
   Hydrogen value chain: from source to consumers
   To ensure effective decarbonization, it is crucial to utilize green hydrogen for the mentioned
   applications. Let’s take a closer look at the hydrogen value chain, tracing its journey from
   source to consumers.

Currently, most hydrogen is produced from fossil fuel sources through processes like steam
methane reforming (SMR) or coal gasification. In fact, over 98% of hydrogen produced today
is categorized as grey hydrogen. To differentiate between hydrogen types, let’s briefly recap
the colour scheme:
 Gray hydrogen – produced through conventional methods using fossil fuels.
 Blue hydrogen – like grey hydrogen, but with carbon capture, utilization, and storage
(CCUS) technologies applied to mitigate emissions. Recent studies have indicated
that blue hydrogen is not significantly different from grey hydrogen in terms of
emissions.
 Green hydrogen: produced using renewable electricity and water electrolysis,
separating hydrogen molecules from oxygen. While electrolysis is not a new
technology, the cost of producing hydrogen through this process has been prohibitive
until recent years when costs have started to decline.
 White hydrogen – refers to hydrogen sourced from natural reservoirs, but these
reserves are rare and insufficient to meet global hydrogen demand.
Currently, green and blue hydrogen together account for less than 2% of the world’s
hydrogen production. Gray hydrogen remains dominant, contributing to around 98% of the
hydrogen market. It is important to note that hydrogen production itself is responsible for
approximately 3% of global emissions, only slightly lower than emissions from the mining
industry, which range from 4% to 6%. Achieving decarbonization of hydrogen production
would require three times the renewable power generated worldwide in 2019. In today’s
hydrogen value chain, the major consumers of hydrogen are ammonia, methanol, and
refineries, accounting for over 94% of global production. The emerging applications, such as
the steel industry, consume less than 6% of hydrogen produced. The demand for hydrogen
is projected to increase by 90% by 2030, with green and blue hydrogen expected to account
for over 50% of that demand. Additionally, the share of hydrogen consumption in emerging
markets is anticipated to grow by another 8%, reaching up to 14% of total hydrogen
consumption.
Understanding the physics of hydrogen and its implications
To evaluate the suitability of hydrogen for the applications mentioned earlier, it is important
to consider its physical properties and their implications. Two key characteristics of an ideal
fuel are high energy content and high flame temperature. Hydrogen possesses both these
qualities, with a higher flame temperature compared to natural gas and 2.5 times more
energy content per unit mass. However, hydrogen has a very low density, meaning it
contains nearly three times less energy per unit volume compared to natural gas. This
necessitates the transfer and compression of a significantly larger amount of gas to achieve
the same energy output. Furthermore, the liquification of hydrogen for transportation is
challenging due to its extremely low boiling temperature near absolute zero. The liquification
process results in a loss of approximately one-third of the hydrogen’s energy content.
Challenges and considerations
The use of hydrogen in mining applications presents several challenges and considerations:

1. Low round-trip efficiency – conversions between different forms of energy result in energy
   losses of around 60 to 70%. Compared to direct electrification, using hydrogen as an
   intermediary requires two to three times more electricity, resulting in higher costs.
2. Storage and transportation – the existing infrastructure for storing and transferring natural
   gas is inadequate for hydrogen use. Hydrogen is a tiny molecule prone to leakage, and
   causes steel embrittlement, which means significant updates and modifications are
   necessary to the current infrastructure. Also, hydrogen must be stored at high pressures of
   approximately 400 to 700 bars. These challenges contribute to higher costs.
3. Competitive market – conventional industries such as ammonia and methanol also require
   decarbonization, and hydrogen serves as their primary feedstock. As a result, competition
   for hydrogen supplies may impact prices.
   Solutions for successful implementation
   To overcome the challenges associated with hydrogen use, the following solutions can be
   considered:
4. Decentralized production – on-site hydrogen production should be prioritized to reduce
   transportation requirements and dependence on larger markets. This localized approach
   enhances supply chain resilience and reduces costs and inefficiencies associated with long-
   distance transportation.
5. Long-term storage – hydrogen should primarily be considered for long-term seasonal
   energy storage requirements possibly in remote sites where seasonal weather patterns are
   drastically different.
6. Niche applications – hydrogen for thermal supply should only be considered when it can
   also be used as a reducing agent and where full decarbonization is not possible with
   electrical energy. Careful assessment of each application’s feasibility and financial viability is
   crucial to ensure the optimal use of hydrogen.
   While hydrogen technologies have potential in the mining industry as the world aims to
   decarbonize and address climate change, it is important to recognize that hydrogen is not a
   universal solution. In most cases, prioritizing electrification over hydrogen is the more
   sensible choice. Electrification should always be the primary focus, as it offers numerous
   advantages. Hydrogen, on the other hand, should be considered a niche market with specific
   applications. It is essential to carefully evaluate each situation and explore alternative
   options before deciding to adopt hydrogen. While hydrogen presents benefits such as fleet
   decarbonization, energy storage, and electricity generation, it also introduces challenges
   related to efficiency, storage, transportation, and market competition. Therefore, it is crucial
   to approach hydrogen implementation in the mining sector with caution and as a
   complementary solution.

 
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