By Andrea Svendsen, Managing Editor.
There’s no question that aluminum is a sustainable material option for industries such as automotive, transportation, and building and construction, among others. The metal’s light weight, high strength, corrosion resistance, and other properties enable engineers and designers to optimize their products, enabling them to develop sustainable, energy efficient designs. In addition, the recyclability of aluminum ensures that it continues to have value and can be reused long after the products’ end of life, as well as significantly decreasing the amount of energy consumed during production.
As customers increasingly look toward decarbonizing their entire supply chain, however, aluminum companies are pushing their sustainability efforts even further — with the ultimate aim being to achieve net-zero carbon emissions in the future. To that end, companies are working to eliminate their GHG Protocol emissions, including Scope 1 (direct emissions from the manufacturing process), Scope 2 (emissions from electricity generation), and Scope 3 (emissions generated externally, such as raw material supply).
One decarbonization method being readily pursued is the use of hydrogen as a replacement for natural gas in combustion. This has the potential to substantially reduce emissions in high temperature processes, such as aluminum melting and recycling. As a result, aluminum companies are investing millions to explore the use of hydrogen in their casthouses.
Development and Production of Hydrogen Fuel
Hydrogen is a plentiful, non-toxic, and highly combustible element that can be burned to produce heat with water being the only emissions produced. Therefore, it has widely been considered as a possible alternative to fossil fuels. In fact, researchers and scientists have pursued the concept of using hydrogen as a fuel to power industrial processes and engines for more than a century. In 1806, Isaac de Rivaz developed what could arguably be called the first internal combustion engine, which used compressed hydrogen gas as its fuel source.1 Later developments included hydrogen fuel cells (first wrote about by Sir William Grove in 1838), along with experimental engine developments for automobiles and aircraft.2
In recent years, hydrogen is actively being considered as a clean energy alternative to fossil fuels for high-emission industries, such as aluminum, steel, glass, and cement. Switching from natural gas to hydrogen comes with a certain number of challenges, including storage and safety concerns (hydrogen is lighter, more prone to leaks, and highly explosive), lack of existing infrastructure, and lack of a strong supply chain.
Since hydrogen does not naturally occur in large enough quantities to be widely used as a fuel source, it has to be manufactured — with associated costs and environmental impact. More than 90 million tonnes of hydrogen was consumed worldwide in 2020 (mainly used in oil refineries and ammonia production), and global demand is expected to grow to 150 million tonnes by 2030.3
There are a range of methods for producing hydrogen, with associated color classifications (Figure 1).4 The least expensive methods of production include brown and black hydrogen (produced using coal) and grey hydrogen (produced using natural gas or methane). Brown, black, and grey hydrogen represent around 99% of world production and have a high carbon content of around 6.6–9.3 t CO2/t H, resulting in 900 million tonnes of CO2 being emitted annually.5 This essentially mitigates the potential environmental benefits of using hydrogen as a fuel.
Blue hydrogen improves the environmental performance, but adds some additional cost. It is primarily produced using natural gas, but is combined with carbon capture to trap and store any carbon produced. Blue hydrogen is considered by many to be a good balance between cost and lower carbon production.
From an environmental perspective, green hydrogen is the best option. The method uses renewable energy to split water molecules into hydrogen and oxygen, with no greenhouse gases being emitted as a result. Despite the benefits of this method, it is considered to be comparatively expensive, and more development is needed to drive costs down.
In response to this need, the U.S. Department of Energy (DOE) announced $750 million in funding to support the development of clean hydrogen projects through the Bipartisan Infrastructure Law. The fund will support 52 projects across 24 states aimed at advancing electrolysis technologies and improving clean hydrogen manufacturing. This is expected to increase U.S. manufacturing capacity to produce an additional 1.3 million tons of clean hydrogen per year.
A number of global gas suppliers and burner manufacturers are exploring a variety of methods of efficiently and cost effectively producing hydrogen for the aluminum industry. Air Products has over 65 years of experience producing, storing, and delivering liquid hydrogen and compressed hydrogen gas to customers. Focused on blue and green production methods, the company initiated two blue hydrogen projects, including its Edmonton net-zero hydrogen energy complex in Alberta, Canada, and the Louisiana clean energy complex in the U.S.6 In addition, Air Products has announced new green hydrogen projects, with three in the U.S. (located in New York, Texas, and Arizona) and one in Saudi Arabia.
Fives Group manufactures advanced technologies for aluminum and other industries, with more than 100 years of experience in industrial combustion and over 50 years of experience in hydrogen technologies. In July 2024, the company signed an MOU with Lhyfe, a producer of green hydrogen using water electrolysis, to develop complete hydrogen-based combustion systems. Lhyfe started operation of its first green hydrogen plant powered with renewable energy in late 2021, followed by two additional facilities in 2023. The company also has plans to build or expand several other hydrogen production sites across Europe. Under the agreement, Lhyfe will produce and supply green hydrogen, and Fives will develop optimized and safe hydrogen solutions for industrial combustion.
Messer Group supplies aluminum and metals processing industries with a diverse range of gases, with 40 years of innovations. The company operates a diverse network of clean hydrogen sources in North America and around the world. The company formed an agreement with the district of Düren in July 2024 to form a new joint venture, called HyDN GmbH. The venture will operate a new green hydrogen production facility, in which two hydrogen electrolyzers and two diaphragm compressors for pressurizing the hydrogen will be installed by Neuman & Esser. The site will have a production capacity of up to 180 kg of hydrogen per hour and will be the largest hydrogen production plant of its kind in Germany. The plant is expected to start operation in 2025.
Hydro Havrand is a business unit set up by Norsk Hydro in October 2021 that will specifically focus on the development of green hydrogen. The unit plans to develop and operate green hydrogen facilities and provide guidance and expertise to enable manufacturers to make the transition to renewable energy. This includes setting up hydrogen production plants near aluminum facilities to generate enough hydrogen for the plant along with other industrial or consumer sectors in the local area. Hydro Havrand furthered its goals by signing an MOU with Shell New Energies Holding Europe B.V. in November 2021. Together, the two companies will construct facilities near their existing operations in Europe, with the aim of producing and supplying hydrogen produced using renewable electricity.
Tenova is a worldwide supplier of sustainable solutions for aluminum and other metals industries, from combustion equipment to furnaces to rolling mills. In January 2022, the company formed an agreement with Snam, an energy infrastructure operator in Europe, to collaborate on the design of integrated combustion systems based on the use of green hydrogen. Snam will contribute its technical knowledge in the production and transport of hydrogen, while Tenova will bring its expertise in designing combustion systems using a blend of gases (up to 100% hydrogen) for furnaces. The collaboration is being carried out in the laboratory under construction at Tenova’s headquarters in Castellanza, Varese, Italy, along with installations and production tests at industrial sites.
Aluminum Producers Investigate Hydrogen
Converting from natural gas to hydrogen in aluminum melting and recycling operations requires minimal infrastructure changes within the plant (such as the installation of new burners and possibly the furnace lining), which makes switching more economically viable. However, there are potential operational challenges to consider. The primary concern is ensuring the safety of employees through proper delivery, storage, and handling of the hydrogen. Another consideration is the effect of hydrogen-use on the quality of the cast product. Hydrogen burns hotter than natural gas and also increases the amount of water vapor in the off-gas,8 both of which could potentially increase oxidation in the melt. Finally, the lifetime and performance of the furnace when using hydrogen needs to be reckoned with. Aluminum companies are taking all of these concerns seriously as they conduct their research into hydrogen use within their facilities.
Constellium
Focused on decarbonizing its operations, Constellium is working to be ready when green and affordable hydrogen becomes commercially available. The company has been conducting laboratory-scale trials at C-TEC, its primary R&D center, and is involved in a number of multi-stakeholder projects. One key project is Hydrogen Technologies for Decarbonization of Industrial Heating Processes (HyInHeat), an initiative funded by the European Commission. “This initiative explores the potential for replacing natural gas with hydrogen in aluminum and steel transformation processes,” explained Pierre-Yves Menet, R&D group manager, Casting & Recycling, Constellium. “The project includes four aluminum demonstrators, with the C-TEC site being the most advanced among them. We plan to provide more information as it becomes more statistically representative.”
Following the completion of laboratory-scale trials and a demonstration phase, conducted at C-TEC, Constellium decided to move forward with industrial-scale testing. In preparation for this next industrial-scale phase, one of the furnaces at C-TEC was outfitted with a new burner that is capable of operating with oxygen and both natural gas and/or hydrogen.
“When using hydrogen as a fuel, the distribution of power within the furnace must be carefully managed,” said Sylvain Henry, vice president of R&D at Constellium and director of C-TEC. “While hydrogen can replace natural gas relatively easily, it is crucial to note that the power injection cannot be adjusted arbitrarily. Proper management of power distribution is essential to ensure that the furnace operates efficiently and effectively with hydrogen, avoiding potential issues related to combustion and temperature control.”
In July 2024, C-TEC successfully completed its first industrial scale casting using hydrogen in a 12 ton furnace. The team implemented strict internal procedures and protocols to ensure the safety of personnel while operating the furnace. Quality monitoring of the melt was conducted using the Batscan™ inclusion detection tool. It was found that the use of hydrogen had no adverse impact on oxidation or metal quality. A 12 ton aluminum slab was produced during testing (Figure 2), which was delivered to Constellium’s plant in Neuf-Brisach, France, where it will be further processed into aluminum sheet for use in electric vehicles.
According to Constellium, this is a significant milestone in its work toward decarbonizing its casthouse operations with hydrogen. The company plans to continue its development of this technology, with additional melting trials to be conducted through the end of 2024 and the first half of 2025. This will further validate the company’s working hypothesis and test the performance of hydrogen in repeated runs.
“During our tests at C-TEC, we successfully validated that we are technically capable of replacing natural gas with hydrogen,” said Henry. “We managed to overcome most of the challenges associated with using hydrogen and aim to be ready to transform our processes as soon as decarbonized hydrogen becomes readily available at an affordable price.”
Hydro
Hydro announced its intention to explore hydrogen’s potential in 2021, when it introduced its new subsidiary, Hydro Havrand. The new business unit is working to develop and operate new green hydrogen facilities, with the aim of supplying green hydrogen to aluminum and other industries. In addition, it is developing commercial fuel switch solutions applicable for the aluminum industry, as well as supporting the testing and trialing of hydrogen as a combustion fuel in melting furnaces.
Hydro completed one such trial in June 2023, when it successfully produced a batch of aluminum billet using green hydrogen at its extrusion plant in Navarra, Spain. The project was conducted in collaboration with Havrand and Fives, which provided its expertise in the design of hydrogen burners. Hydro implemented a number of safety procedures to ensure the safety of personnel during the trial, which was conducted on a 27 ton tilting melting furnace outfitted with TwinBed regenerative burners capable of using hydrogen or a blend of hydrogen and natural gas. No other modifications were made to the furnace.
Using hydrogen or a hydrogen-natural gas mix, the Navarra casthouse was able to produce more than 100 tons of billet in several different aluminum alloys under various process conditions. The results were generally positive, with the use of hydrogen showing no significant productivity losses, no major impact on quality, and no unsafe incidents. The recycled aluminum produced in the trials was delivered to Irizar e-mobility, a Spanish company that produces electromobility solutions, which used the profiles in the bodywork of their electric vehicles, such as the “ie tram,” a zero-emission bus with the appearance of a tram.
Building on the knowledge gleaned from the Navarra trials, Hydro now plans to launch a three-year industrial-scale pilot at Hydro Høyanger (Figure 3), its new recycling unit opened in Norway in mid 2024. “Built from scratch, Høyanger provided us with a unique opportunity to incorporate hydrogen infrastructure into the plant design from the drawing board,” said Kristin Karlstad, head of Communication & Public Affairs, Hydro Aluminium Metal. “Now that the decision has been made to go forward with the pilot, we are proceeding to install polymer electrolyte membrane (PEM) electrolysis with a buffer tank to produce and store smaller amounts of hydrogen. So, it’s a matter of getting the equipment in place rather than redesigning the facilities.”
One of the remelting furnaces will be powered by green hydrogen over the course of the pilot, which will provide insights into the metal quality and decarbonization potential of the technology. The pilot will also contribute information on fuel switch technology and the infrastructure required to use green hydrogen on an industrial scale. The project is supported by Enova, an enterprise established by the Norwegian Government, which granted up to NOK 83.3 million (US$7.67 million) in soft funding.
“Introducing hydrogen in the aluminum industry only makes sense if we use renewable electricity to split water molecules into hydrogen and oxygen, without emitting greenhouse gases,” noted Karlstad. “This is the case for Norway, where an energy matrix based on renewables is what already allows Hydro to deliver primary aluminum with a carbon footprint of about one fourth of the world average. Still, we are convinced that green hydrogen has the potential to play a key role in the global transition to a sustainable and zero-emission economy. We are looking forward to gaining more experience with the Høyanger pilot and are determined to do our part to develop fuel switch solutions that will allow green hydrogen to be used not only in the aluminum industry, but other hard-to-abate industries as well.”
Novelis
As part of its sustainability goals, Novelis Inc. is actively investing in technologies and projects aimed at reducing its Scope 1–3 emissions. The company’s research and development teams worldwide are also investigating the ability to use various lower-carbon fuel sources, such as hydrogen, plasma, and electric heating to power melting and heat treatment processes.
For years, the company has been conducting technical feasibility studies on replacing natural gas with hydrogen. In line with this research, Novelis joined HyNet in 2017, an initiative that supports the development of a regional U.K. infrastructure project for the production, transport, and storage of low-carbon hydrogen. The initiative also conducts technical feasibility studies on the use of hydrogen as a direct substitute for natural gas.
Through HyNet and with £4.6 million (US$6.02 million) in funding from U.K. Government’s Industrial Fuel Switching Competition (part of the £1 billion Net Zero Innovation Portfolio), Novelis plans to establish hydrogen burning trials at its recycling plant in Latchford, U.K. (Figure 4). Set up in collaboration with Progressive Energy, an independent U.K. energy company, the trial will test the use of hydrogen on one of the site’s recycling furnaces in a demonstration phase that will be conducted between October 21 to November 1 in 2024.
Conducting the trial requires specific furnace modifications. New industrial and regenerative burners need to be installed that are capable of operating using either pure hydrogen or a blended hydrogen and gas fuel. In addition, the furnace lining material will be replaced with one better suited for hydrogen burning. A temporary supply of hydrogen will be delivered via road tankers to Latchford, which necessitates significant adaptation to the plant’s existing infrastructure to ensure safe handling of the new fuel.
During the trials, technicians will conduct several tests using percentage blends of hydrogen with natural gas, starting with a 10% hydrogen blend and going up to 100%. A selection of aluminum alloys will be recycled, allowing for all relevant operational and product parameters to be assessed, including any impact on the product, process, operational environment, and environmental emissions. A significant part of the demonstration project will also be dedicated to the technical design and safety assessment of the trials.
“This is a great pilot opportunity to test the possibilities of using hydrogen,” said Thomas Kampen, director of Strategy & Sustainability, Novelis Europe. “Through the operation of hydrogen burners in our furnaces, we can gain firsthand experience of any effect on equipment lifetime, obtain data on NOx emissions from hydrogen operation, build experience in the safe operation of hydrogen in populated manufacturing environments, and establish the relevant standards and impact on wider plant operations.”
According to Novelis, implementing hydrogen in its remelting furnaces could reduce carbon emissions by up to 90% compared to using the same amount of natural gas (depending on the final configuration). “Once we have the full picture from the trials and wider project will we be able to determine the speed and scale of any further adoption of hydrogen,” noted Kampen. “In general, switching to renewable energies is a key lever at all of our plants to decarbonize our melting processes and with that further decarbonize our product offering to the market. At the same time, the hydrogen economy needs to scale rapidly so that companies like ours can plan for the creation of the necessary hydrogen storage and supply infrastructure as well as the expectation of a long-term affordable price base for this new fuel.”
Trimet Aluminium
Trimet Aluminium SE, headquartered in Essen, Germany, announced its commitment to promoting a sustainable and viable hydrogen industry in the region in 2021, when company’s CEO, Philipp Schlüter, joined the city’s H2 Advisory Board, an initiative instituted by Essen’s Lord Mayor, Thomas Kufen. Bringing together representatives from companies and research establishments, the Advisory Board aims to support the development of new innovations and future projects.
As of Autumn 2024, the company is implementing hydrogen-rich energy gas to operate some of the melting furnaces at its recycling plant in Gelsenkirchen, Germany. The hydrogen-rich gas will be supplied by Uniper Energy Sales. The gas is a by-product obtained from a coking plant operated by ArcelorMittal in Bottrop (around 15 km away), which will be delivered to Trimet’s plant using existing gas pipelines, with a new 700 m extension to connect it to the recycling plant. Containing more than 60% hydrogen, the hydrogen-rich gas from the coking plant emits significantly fewer emissions than fossil fuels and will save around 4,000 tons of CO2 per year at the recycling plant. The company will consider switching the entire Gelsenkirchen operation over to hydrogen, as long as the gas remains commercially available and economically viable.
Other Aluminum Companies
The four companies already mentioned only represent a small portion of those that are exploring the use of hydrogen in a wide range of operations, from alumina refining to primary aluminum production. Some of the projects underway include the following:
- In February 2022, Aluminium Bahrain B.S.C (Alba) signed an MOU with Bahrain Petroleum Company (BAPCO) to collaborate on various sustainability initiatives.9 This includes a feasibility study on the supply of hydrogen from BAPCO to Alba for power production.
- In April 2024, Emirates Global Aluminium (EGA) signed an agreement with Masdar, a clean energy company, to explore the joint development of renewable energy projects, including green hydrogen production and storage projects.10
- In July 2023, Rio Tinto signed an agreement with Sumitomo Corporation to develop an A$111.1 million project aimed at demonstrating the use of hydrogen at the Gladstone alumina refinery in Australia.11 A hydrogen production plant will be constructed at the refinery, along with a retrofit of the calcination equipment, where hydrated alumina is heated up to 1,000°C. If the use of hydrogen is determined to be viable, it could reduce emissions by 500,000 tonnes per year.
Conclusion
Hydrogen fuel provides significant potential for decarbonizing a variety of industries that implement high-temperature processes, such as aluminum recycling and remelting. However, exploiting that potential requires solving some considerable challenges regarding the decarbonization of the hydrogen production process and bringing the cost of hydrogen down to a viable rate. Fortunately, the amount of collective investment from both hydrogen suppliers and the aluminum industry in the development of hydrogen fuel technologies is impressive. If hydrogen gas suppliers can continue to expand their low carbon production capacity and aluminum companies are able to successfully complete their hydrogen combustion trials, then hydrogen just might become the fuel of the future for the aluminum industry.
References
- “De Rivaz engine,” Wikipedia.
- “Timeline of hydrogen technologies,” Wikipedia.
- “Hydrogen Factsheet,” Center for Sustainable Systems, University of Michigan, 2023, Pub. No. CSS23-07.
- “The hydrogen colour spectrum,” National Grid.
- Svendsen, A., “Hydro Trials the Use of Hydrogen in its Recycling Operations,” Light Metal Age, Vol. 81, No. 4, August 2023, pp. 22-25.
- “Biden-Harris Administration Announces $750 Million to Support America’s Growing Hydrogen Industry,” U.S. Department of Energy, March 13, 2024.
- Schoonover, M., et al., “Low Carbon-Intensity Hydrogen Production Pathways, Distribution, and Use in Secondary Aluminum Melting,” Light Metal Age, Vol. 82, No. 2, February 2024, pp. 42–45.
- “The challenges of the HyInHeat project,” HyInHeat, September 10, 2023.
- “Alba and BAPCO join forces to foster Green and Sustainable Industrial Development,” Alba, February 6, 2022.
- “Masdar and EGA form alliance to work together on aluminium decarbonisation and growth through renewables,” Masdar, April 17, 2024.
- “Rio Tinto and Sumitomo to build Gladstone hydrogen pilot plant to trial lower-carbon alumina refining,” Rio Tinto, July 12, 2023.
Editor’s Note: This article first appeared in the October 2024 issue of Light Metal Age. To receive the current issue, please subscribe.