Comment: The route to greener steel

In addition to valid political questions around stable energy sources, supply reliance on other countries and job losses from the Port Talbot closures, making steel in the UK comes at a cost. Yet the steel industry cannot stand still and massive change is needed for the industry to reduce its carbon footprint 

The carbon conundrum

Making virgin steel is carbon intensive. For every tonne of steel produced via a blast furnace, around 2.5 tonnes of CO2 are emitted.  Changing to electric arc furnaces (EAF) which use recycled scrap as the main input reduces the amount of CO2 emissions significantly, to around 0.5 tonnes of C02 per tonne of steel. The majority of UK steel production used in the construction industry relies on virgin steelmaking through the blast furnace route, thus access to these significant carbon reductions available from EAF production is currently limited to imported steel. Understandably then, there is increasing pressure on UK steel suppliers to develop routes to produce lower carbon-emission steel in order to compete with European producers.

Supply chain and energy

The shift to EAFs requires significant changes in the supply chain. Instead of importing high-carbon iron ore and coal, the new process will rely on high-quality scrap metal, of which the UK has a strong domestic supply and is currently a net exporter.

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Improvements in scrap sorting and advances in EAF technologies are also increasing the range of products for which the process can be used, having been previously limited due to issues with quality control of the scrap input.

It is important to note that whilst switching to EAF production in the UK will reduce the carbon emissions of UK steel production, it is not a silver bullet to carbon emissions. EAF production is also not net-zero of itself, with a much greater electricity demand than virgin steel production, further reductions in emissions are reliant on the de-carbonisation of the UK’s energy network.

Wider industry change

Globally the quantity of available scrap steel is insufficient to meet the demand for new steelwork, so if the UK begins to retain much of its scrap for recycling into new steelwork rather than exporting, it will likely result in an increase in virgin steel production elsewhere, offsetting some of the benefit of the UK’s reductions.

Globally getting to net-zero steel production is hugely ambitious and the industry cannot rely solely on looking to recycling of steel through EAF production to achieve this. There is still a great demand for virgin steel production and to develop methods to reduce the carbon intensity of this production route. Wholescale change and investment are needed across the global industry for that to become a reality. Numerous studies and test plants are investigating methods of carbon capture and storage and production of steel using hydrogen instead of carbon is a proven technology, but one which is reliant on a cost-effective supply of green hydrogen.    

 Tom Kember is Associate Director at Buro Happold