Lack of industry standards for green steel won’t hinder adoption by construction sector: ArcelorMittal
Government purchasing pledges, new products and changing attitudes toward building design are bringing standards closer
The lack of an industry-wide definition of “low-carbon steel” will not hinder its adoption by the construction sector, Olivier Vassart, chief executive of ArcelorMittal Steligence said. Government purchasing pledges, new products from steelmakers and a change in attitudes toward building design are bringing standards closer.
“Ask 20 people in steel and construction ‘What is green steel?’ and you will have 40 different answers. In the absence of standards, the system will come to drive this definition,” he told Fastmarkets in an interview.
Under the Industrial Deep Decarbonization Initiative (IDDI), the governments of the United Kingdom, India, Germany, the United Arab Emirates and Canada pledged at COP26 to purchase volumes of low carbon-emission steel for public projects, giving both industries a unique opportunity to cut emissions.
“This is a really good sign that states themselves will support the development of green steel. If it’s put in place, it will be significant because construction [and] public investment are driving the future,” Vassart said.
“In some areas, the private sector is in front, but also the public sector is taking into account that infrastructure is a big consumer of steel… this will clearly give a push to the development of green steel in the market,” Vassart added.
“It will give additional value to a building which is more respectful of the environment,” he said. “For me, this respectfulness must be applied to the full life cycle of the building. Steel is perfect for the circular economy as [future generations] will be able to recover, reuse or remelt it at a really low environmental cost.”
Construction’s greenhouse gas emissions
The construction sector accounts for around 40% of global greenhouse gas emissions, which comes from materials used - such as steel - as well as heating, cooling, and lighting.
Production of long steel used in construction such as rebar, H-beams, sheet pile, merchant bars and wire rod is done mainly via an electric-arc furnace (EAF) using recycled ferrous scrap. This method produces fewer CO2 emissions than other conventional blast furnace technologies, adding renewable power reduces these emissions further.
“When we [produce] steel with an EAF, we are already by nature at a lower CO2 content than primary steel made using conventional blast furnace technology, thanks to the scrap use,” Vassart said. “If we do a life cycle assessment (LCA) of the final product, one big part of the environmental burden is the production of electricity used to melt the steel, and its production changes from one country and region to another.”
An LCA, which assesses the environmental impact of a product, covers the full scope from cradle to grave, including alloys and purchases for steel making.
Using renewable power and recycled scrap reduces the CO2 footprint and scope 2 emissions. ArcelorMittal has EPDs for rebar of 300kg of CO2e per tonne, 333kg of CO2 per tonne for h-beams and 370kg of CO2 per tonne for sheet pile.
This represents as much as half the emissions compared with H-beams produced in an EAF operated using non-renewable energy, which has a CO2 emissions intensity of 600-800kg per tonne. For primary steel produced via blast furnace, the industry average CO2 is 2,200kg per tonne.
“Steel already has strong sustainability credentials, as it is infinitely recyclable. That’s something the steel industry needs to explain to everyone,” Vassart said. “It costs CO2 to produce steel - that’s clear; we cannot deny this - and we have clear goals to reduce our CO2 emissions by 35% within ArcelorMittal Europe by 2030 and net-zero by 2050. We also need to look at what would be the alternative cost to the environment.”
“Even with a reduction of the emissions, using the right steel in the right place, you are already significantly emitting less CO2 to build than many alternatives. For me, steel is already green by essence - it’s already circular - but we are doing more to decrease this footprint,” Vassart said.
The company purchases scrap within a radius of approximately 200km of the mills. The industry is nearing 95-100% recovery of steel scrap, Vassart said, with the volume of scrap available in the loop constantly growing.
The extra costs of green steel give additional value to the construction sector, he said.
“The impact of a premium is small, on the scale of a building. In a building, you have a maximum of 40kg per meter square build; if the building is made with green steel with a premium of €100 per tonne, for example, that’s less than €4 [extra] per meter square.”
He also believes the European Commission (EC) will bring in legislation to force people to decarbonize, similar to how energy efficiency regulations have been created.
“[The EC] will progressively decrease the threshold to force people to decarbonize,” he said. “We saw the same tendencies one decade ago with the energy efficiency of buildings. I expect this will come for embedded CO2.”
Alongside regulation, premiums and bonuses could help building designers and owners to decarbonize, Vassart added.
The UK uses the London Energy Transformation Initiative (LETI) to restrict carbon in construction. The incoming embodied carbon rules for France and the Netherlands will bring guidance on the maximum amount of CO2 per square meter of the build.
Construction and recycling
The construction sector is already active in recycling, with 99% of steel from a demolished building being recovered and recycled. But for Vassart, the full life cycle and beyond must be considered from the design stage.
“We need to support the construction industry to design the non-obsolescence of the building,” he said. “We need to support them and help them to build buildings that will live longer. Then we can easily transform and repurpose [buildings] in order to increase their life span.”
“Steel has the highest level of recycling of all materials,” he said. “We need to think beyond this and think about the repurposing and reuse of steel when possible.”
Designers have massive leverage to optimize the use of steel, especially low carbon steel, which can decrease the carbon footprint of a building by 50-60% compared with traditional building methods.
“As a steel producer, we are doing our duty to decarbonize steel production and to be able to put decarbonized material on the market,” Vassart said. “We have a role to play by offering more environment-friendly material. Designers also have a really big role to play by choosing the right material and using it in the right place where it makes sense, but also using the right steel.”
Demand for ArcelorMittal’s reduced-carbon long steel products following the launch earlier this year of XCarb recycled and renewably produced steel (steel made in an EAF, using a high proportion of scrap and 100% renewable electricity) has grown and will continue to grow in the coming years, Vassart said. This is thanks to designers and building owners seeking out such alternatives to decarbonize their projects.
“It is a market under development … We need to let the market digest this potential,” he said.
The future of green steel
From concept and design to actual purchase and delivery, it can take five to ten years to construct a landmark building, meaning now is the time for decarbonization and alternative materials to be on building designers’ agendas.
Green steel will appear in building designs and bidding documents, and it will be used by construction companies in several years, Vassart said.
As the final customer, the building owner ultimately decides on the use of green steel.
“The ones which have the biggest leverage on the use of greener material are the building owners and engineering offices,” Vassart said. “For construction firms, they also want to be seen as greener. They are also looking at the way they build - some of them are proposing to the building owner to build it more responsibly,” he added.
“If we look at the sheet pile application, the decision is much more in the hands of public authorities, as we are mainly talking about infrastructure investments,” he said. “This is why a lot of projects have already been delivered in EcoSheetpilesPlus.”
“We cannot put our waste on the next generation. With XCarb recycled and renewably produced [steel] already available on the market today, we are on the right path,” Vassart said.