The Steel Industry in the European Union on the Crossroad to Carbon Lean Production—Status, Initiatives and Challenges

The European steel industry is the second largest steel producer worldwide generating 168 million tons of steel at more than 500 production sites across 24 EU member states in 2018 [1]. Steel production is either based on iron ore or scrap, whereby the shares of the individual routes differ significantly depending on regional circumstances. The current available crude steel production routes are shown in Fig. 1.

The two predominant steel production routes in EU27 are

The production of steel from iron ore is highly reliant on carbon. Consequentially, CO₂ is generated within the steel making process resulting in 1718 kg CO₂ per ton of crude steel. In 2016, the steel production accounts for 5% of all CO₂ emissions across EU28 [2, 3].

The EU, which accounts for 10% of global GHG emissions, intends to become climate-neutral by 2050. In 2009 the EU declared an 80–90% reduction of its emissions by 2050. Recent decades have successfully demonstrated that it is possible to increase the gross domestic product, while reducing energy consumption and GHG emissions. This indicates the feasibility of decoupling these emissions from the economic growth. In 2018 the EU commission defined a vision and long-term strategy for a modern, competitive, prosperous, and climate neutral economy. The foundation for joint actions are provided by the following seven main strategic building blocks [4]:

A substitution of the BF/BOF route through the scrap based EAF route leads to a possible CO₂ mitigation of about 25% per ton of steel depending on the energy mix applied. Although the emissions of this route are likely to be further diminished by steadily increasing electrical energy production from renewable energy, the application of this route is limited in terms of availability and quality of scrap. Another alternative is direct reduction, whereby coal is replaced by natural gas as an energy source and reducing agent. This process generates direct reduced iron (DRI), which is subsequently melted to crude steel in the EAF. The reduction potential in comparison to the BF/BOF route is about 35% [5]. Hot metal production with smelting reduction technologies is based on coal, and, unless combined with Carbon Capture and Usage (CCU) technologies, the CO₂ emission cannot be reduced significantly in comparison to the BF including sintering and cokemaking.

Another opportunity for anthropogenic CO₂ mitigation is the utilisation of solid biomass within metallurgical processes, whereby additional treatment steps (e.g. torrefication, pyrolysis) are required. A challenge is the availability of biomass in EU27, since the demand for biomass in other industrial sectors (pulp and paper, natural fibres, or chemicals) will increase within the next decades. A complete substitution of coal in the BF/BOF route with biomass is not possible [6].

Process optimisations and breakthrough technologies will inevitably be required and may be associated with large infrastructure costs. This would likely induce an increased price of produced steel having a negative impact on the competitiveness of the European steel industry. A transition towards a CO₂ lean steel production is directly proportional to a higher consumption of electrical energy and will entail significant modifications regarding the production and distribution of energy. The decarbonisation of the energy sector is therefore one of the prerequisites for reducing GHG emissions from steel production, and the availability of renewable energy must be ensured. The conversion will have to take place in parallel with regular production and must neither affect standard operation nor the quality of the product [7].

The EU steel industry is urged to improve its processes and develop innovative approaches to reduce its CO₂ emissions. Therefore, the European steel producers have launched various projects for CO₂ mitigation focusing on the technological pathways SCU and CDA. SCU includes the pathways Process Integration (PI) and CCU. At this point, it must be mentioned that, within the RFCS projects LowCarbonFuture and GREENSTEEL, various mitigation technologies are evaluated, obstacles are identified, and necessary framework conditions as well as possible approaches for a successful transition are developed [8].

The climate targets of the EU and their fulfillment by 2050 will result in major changes, which are accompanied by technical, political and social challenges for the European steel industry.

A secure and healthy industrial base in the EU, careful handling of EU imports and fair trade need to be ensured to prevent a possible delocalisation of steel production to non-European countries (carbon leakage) and negative effects on European competitiveness. The conversion towards a CO₂ lean steel production requires a detailed evaluation and analysis of the various mitigation technologies and their integration into existing plants. The development of different mitigation technologies is affected by local circumstances and boundary conditions, and it is highly probable that different technologies evolve in parallel resulting in a diverse industrial environment. The different technologies should be implemented by plannable, smart, and affordable steps and several kinds of bridge technologies will probably be necessary.

An essential prerequisite for the implementation of decarbonisation technologies, whether they rely on electricity, hydrogen, or other renewable sources, is the availability of low carbon energy. Finally, an industrial symbiosis, i.e. sector coupling, must be considered, since the exchange of energy and material streams (by-product from one process as secondary raw material for another sector) will help to reduce the demand of primary resources and will contribute to an increased circular economy.