HYBRIT – A journey toward fossil-free steel

HYBRIT – A journey toward fossil-free steel

In 2016, SSAB, LKAB and Vattenfall joined forces to create HYBRIT – an initiative that endeavours to revolutionise steelmaking.

HYBRIT (Hydrogen Breakthrough Ironmaking Technology) aims to replace coking coal, traditionally needed for ore-based steelmaking, with hydrogen. The result would be the world’s first fossil-free steel production technology, with virtually no carbon footprint.

During 2018, work started on the construction of a pilot plant for fossil-free steel production in Luleå, Sweden. The goal is to have a solution for fossil-free steel by 2035. If successful, the HYBRIT project alone could reduce Sweden’s carbon dioxide (CO2) emissions by 10% and Finland’s by 7%, respectively. Here, we take a look at this important effort to decarboninse the business of steelmaking and the fundamentals behind the HYBRIT project.

Steel: Growing global demand

Steel is an important enabler for building the modern society, including industry, innovation and infrastructure. But the steel industry is also one of the highest carbon dioxide emitting industries, accounting for up to 7% of global and 10% of Swedish CO2 emissions.

Sweden has set a national target to reach zero net emissions of carbon dioxide by the year 2045, defining the future pathway for the country’s steel industry. Sweden offers favourable conditions for HYBRIT to contribute to these national targets, such as high quality niche production of iron-ore pellets, a specialised and innovative steel industry, and an abundant supply of fossil-free electricity.

Although the HYBRIT route of fossil-free industrial production will face challenges, it offers a great opportunity to reach new global markets for green technology and products., and take a leading position in fighting climate change while strengthening competitiveness.

Decoupling carbon dioxide and energy

The ore-based steelmaking value chain starts at the iron ore mine. After mining, the iron ore is processed, and a product rich in iron oxides is produced in the form of pellets, or fines. At the steelmaking site, iron ore is converted to metallic iron by reduction of the iron ore pellets with coke in a blast furnace. The iron oxide and carbon then react to form CO and CO2 gases, as well as metallic iron. Now in liquid form, the iron is further processed before a semi-finished steel product is cast.

An alternative to the dominant blast furnace ironmaking route is to use the direct reduction process where natural gas replaces coke as the main reductant, and the main product is solid sponge iron. The iron then needs to be melted using an electric arc furnace, before steel is produced. Currently, this gas-based direct reduction process is not used in Sweden, but is an option in other parts of the world where natural gas is in abundance.

The reduction reactions in ironmaking represent around 85-90% of the total carbon dioxide emissions in the ore-based steelmaking value chain. In addition, the energy-containing gas from coke ovens and blast furnaces has an important role as the main energy source for heating furnaces and materials.

Fossil-free steel production will eliminate the formation of CO2, by using fossil-free reductants and energy sources. In the case of HYBRIT, iron metal is produced by using hydrogen gas as the main reductant. The production route is similar to existing direct reduction processes, except for the carbon dioxide emissions: hydrogen reacts with iron oxides to form water instead of carbon dioxide. Hydrogen gas is produced by electrolysis of water using fossil-free electricity, which is already the standard in Sweden.

Study findings

The HYBRIT pre-feasibility study provided encouraging results, with no major, previously unknown technical obstacles identified.

Nevertheless, considerable future development efforts will be required to realise and verify the concept, and to handle the risks. These include research projects using models and laboratory scale experiments, as well as trials in pilot and demo plants. The pre-feasibility study found that:

  • Considering current cost levels, an iron and steelmaking value chain based on the HYBRIT concept would result in a 20-30% increase in the cost of producing crude steel. The cost structures of fossil and fossil-free value chains are strongly dependent on the prices of coking coal, electricity and emission rights.
  • Large-scale hydrogen production and storage will allow for flexibility in power consumption on a large-scale, which will favour the implementation of intermittent renewable energy sources for electricity production.
  • Large-scale hydrogen production will boost the transition to other hydrogen-based technologies and spur innovation and business spin-offs associated to the hydrogen society.
  • Electrical infrastructure expansions and regional transformation support are fundamental requirements for the concept.

Taking the green route

To avoid future emissions, the solutions under development have to be technically and economically viable.

When calculating initial emissions of the current dominant production process, both direct and indirect emissions were included. In Sweden, the carbon dioxide emissions using current technology are 1.6–1.7 tonnes of CO2 per tonne of crude steel, compared to the estimated 2.0–2.1 tonnes of CO2 for a typical integrated steel plant in Western Europe. The result can be explained by differences in the electricity mix, with more renewable sources available in Sweden. Another factor is the high level of energy efficiency in the Swedish industry, where LKAB and SSAB are leading operators in terms of energy efficiency.

Capital costs were estimated for the construction of respective production systems in greenfield conditions. This is, however, a generalisation considering that there is a functioning production system in place that needs to be restructured. Replacing major parts of the existing infrastructure in steelmaking would be very expensive; careful planning is key so that any transition is carried out when previous investments reach the end of their lifecycle.

The main factors affecting HYBRIT in the long run are mainly price developments for coking coal, electricity and emission allowances. If coking coal prices increase, it will benefit the HYBRIT business case; increasing electricity prices will weaken HYBRIT. Future developments of the emission trading system EU ETS will also have an impact.

Although a complete replacement of carbon by renewable energy will result in an increase in material costs, the impact on the end-user product is neglible. Predictions of future costs are highly uncertain, but anticipated shifts in prices and market demands make the HYBRIT concept a more commercially attractive option.

Identified challenges

In order to obtain a viable fossil-free industry, a huge effort to resolve certain issues remains, with major challenges in various areas. The HYBRIT team identified a range of challenges, including:

  • The effect of carbon-free processing must be clarified
  • Hydrogen production will be based on existing commercial technology, yet to be proven on a large-scale
  • Hydrogen storage will also be integral, with technology for large-scale storage still untested
  • Fossil-free fuels and technologies for process heat will be required to replace existing fossil heat sources in the production system
  • An operating practice needs to be established in the new process to function as a stand-alone unit and as part of an optimised value chain
  • The electricity supply and transmission from renewable sources to the future production sites will play an important role
  • Political instruments like emissions trading will affect the industrial transition period and the likelihood of a viable business case
  • The industrial transition stages and associated technological and economic effects represent considerable risks and costs for the companies involved, which need to be resolved.

Going forward

Next year (2020) could be a big year for the HYBRIT initiative. Its roadmap remains intact, and the pilot phase began in 2018, with initial activities aiming to prepare design and construction in order to have a pilot plant operational in 2020.

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