Steelmaking

The future of low emissions steelmaking

Steel is essential to a low carbon future

The world depends on steel every day. Endlessly recyclable, and with the highest strength-to-weight ratio of all building materials, steel’s durability and versatility makes it a trusted foundation for our homes, bridges, hospitals and public transport networks. Importantly, steel underpins the transition to a low carbon future, as it is essential for renewable energy infrastructure.

According to worldsteel, the world produces nearly 2 billion tonnes of steel per year (1,892 billion tonnes in 2023), and looking forward, it must keep pace to meet society's growing needs.

While steel products deliver value to customers in support of their environmental goals, the processes that produce them do require significant amounts of energy and contribute to greenhouse gas (GHG) (also called CO2) emissions. worldsteel reports that the industry generates between 7 and 9 per cent of global CO2 emissions.

Global steel industry 2023 emissions intensity

1.92 tCO2e / tonne raw steel

 

 

BlueScope 2023 and 2024 emissions intensity

FY2023
1.508 tCO2e / tonne raw steel

FY2024
1.443 tCO2e / tonne raw steel

Reducing steelmaking emissions intensity

GHG or CO2 emissions - CO2e (Carbon dioxide emissions) - are measured in terms of intensity in tonnes CO2e per tonne raw steel.

worldsteel data* indicates the global steel industry produces an average emissions intensity for its steelmaking activities of around 1.92 tonnes CO2e per tonne of crude steel cast.

By comparison, BlueScope’s steelmaking activities produced an average 1.51 CO2e in FY2023, and more recently, 1.44 CO2e in FY2024, less than the global average - a trend reflecting our ongoing focus on emissions reduction.

worldsteel observes that throughout the global industry, companies are focused on finding ways to lower their GHG emissions, and new forms of collaboration are emerging to take on the challenge.

* Figures based on 2023 worldsteel data available at Sustainability Indicators 2024 report.

The industry challenge to evolve iron and steelmaking technologykey to reducing emissions

As worldsteel data* indicates, globally, 72 per cent of steel currently produced is ‘new’ or ‘primary’ steel, which starts with the process to first convert iron ore to iron before reducing the iron to steel.  Primary steel is mostly produced in large-scale, integrated steel plants using traditional blast furnace (BF) ironmaking and then basic oxygen furnace (BOF) steelmaking technologies. Direct reduced ironmaking (DRI) is an alternative to the blast furnace route. Currently, however, DRI is available in only a few regions and operates at a significantly lower production capacity.

Approximately 20 per cent of steel produced today is ‘secondary’ steel produced from electric arc furnaces (EAFs), which rely heavily on scrap steel and electricity.

In almost all cases, EAF and combination DRI/EAF technologies are lower in carbon and energy intensity than the BF/BOF combination. Scrap is a very low emissions, recycled material, so increased use of scrap plays a critical role in industry decarbonisation and improving emissions intensity. But there is currently not enough quality scrap to meet global demand for steel, which presents a challenge

For the foreseeable future, the manufacture of primary steel will continue to be a central part of the steel industry, and the world will still rely heavily on integrated steel plants that use BF/BOF technology. As economies mature and more steel reaches the end of its lifecycle, the opportunity to recover more steel for use in EAFs will increase.

Figures based on 2023 worldsteel data available at Sustainability Indicators 2024 report.

BlueScope's iron and steelmaking technologies across the globe

BlueScope’s three steelmaking operations use different iron and steelmaking technologies and raw materials. Both Port Kembla Steelworks in Australia and Glenbrook Steelworks in New Zealand are integrated iron and steelmaking operations producing primary steel, Port Kembla through BF/BOF technology. North Star BlueScope Steel (North Star) is a ‘mini mill’ steelmaking operation, producing secondary steel mainly using scrap as the key raw material processed through an EAF.

These technology terms are explained further in the following section, giving examples of BlueScope's iron and steelmaking technologies - both existing and those being explored. worldsteel also has a wealth of information about the story of steelmaking at worldsteel.org/about-steel/steelmaking-process/.

BF/BOF technology

Blast furnace (BF)/basic oxygen furnace (BOF) technology makes steel broadly in a 3-stage process: the mining of iron-rich raw materials like iron ore, reduction of iron into 'pig' iron, and smelting of pig iron into raw steel.

Firstly, iron-rich iron ore, and carbon-rich coke (sourced from coal) are combined with oxygen in a hot blast furnace (BF). Under extreme heat, carbon-oxygen based gases are generated and act as a reductant to reduce the iron oxide (Fe2O3) within the ore to a molten iron state. (Fe). Chemically:

2C + O2 → 2CO (the carbon-oxygen step to produce carbon-based gas)
Fe2O3 + 3CO → 2Fe + 3CO2 (carbon-based gas reduces iron oxide to molten iron (Fe) and greenhouse gases (CO2)

The iron is smelted in another hot basic oxygen furnace (BOF) that uses oxygen and other additives to remove excess carbon and form steel grades to required quality specifications.

In addition to steel, this BF/BOF technology creates by-products which are further processed, including CO2 which can be recycled around the plant as an energy source, with excess being cleaned and emitted as greenhouse gases.

BF/BOF technology

Blast furnace (BF)/basic oxygen furnace (BOF) technology makes steel broadly in a 3-stage process: the mining of iron-rich raw materials like iron ore, reduction of iron into 'pig' iron, and smelting of pig iron into raw steel.

EAF technology

An electric arc furnace (EAF) is a steelmaking furnace designed to use electricity, in the form of an electric arc, to heat and melt steel scrap and other already processed iron (eg pig iron or hot briquetted iron) to over 1,000°C.

EAFs rely on large amounts of high voltage electricity, where available and viable, generated from low GHG emission or renewable energy. The viability of the EAF process is influenced by several factors, including access to adequate quantities of quality steel scrap and the cost, reliability and emissions intensity of local electricity supply.

BlueScope EAFs

Watch these videos about the EAFs at two of BlueScope's three steelmaking sites, technology that is viable in these instances due to the necessary enablers being in place:

  • Glenbrook's first EAF set to be operational in New Zealand by 2025/6 (above), and 
  • North Star's third EAF commissioned in 2022 in Ohio, North America

For more information on our net zero GHG emissions goal and enablers, see further down this page.

Lower emissions DRI technology

Direct Reduced Iron (DRI) technology offers an alternative method for producing iron, typically without the need for metallurgical coal, unlike the blast furnace process.

DRI is the term given to a group of processes for making iron from ore (in the form of lumps, pellets, or fines) using a heated reducing gas, most commonly natural gas or gas produced from heating coal. The industry is exploring the use of green hydrogen as a reducing gas, however commercialisation remains a challenge. To be converted into steel, DRI needs to be further processed in an EAF or BOF.  As this video describes, we are exploring a DRI process for our Port Kembla Steelworks.

 

 

Our mid-term 2030 targets

In working towards our 2050 net zero goal, we have set interim emissions intensity reduction targets for steelmaking and non-steelmaking activities.

Steelmaking

Targeting a 12 per cent reduction in Scope 1 and 2 GHG emissions from our steelmaking operations by 2030 against a FY2018 baseline (measured as tonnes CO2e per tonne of raw steel produced). This target is equivalent to a 1 per cent year-on-year emission intensity reduction (from 2018) across our steelmaking activities.

Non-steelmaking

Targeting a 30 per cent reduction in Scope 1 and 2 GHG emissions from our midstream non-steelmaking activities by 2030 against a FY2018 baseline (measured as tonnes CO2e per despatched tonne of steel). We report annual performance against these targets in our annual Sustainability Report. and Sustainability Data Supplement.

BlueScope’s climate goal and targets

 

Our 2050 net zero goal

Our goal is to pursue net zero Scope 1 and 2 GHG emissions across our business by 2050.

Scope 1 and Scope 2 GHG emissions

According to common practice, we characterise steelmaking GHG emissions in accordance with the GHG Protocol:

  • direct emissions from our operations are referred to as Scope 1;
  • and indirect emissions from the energy we buy are referred to as Scope 2.

Iron and steelmaking a major focus

Iron and steelmaking activities across our three steelmaking sites (Glenbrook, New Zealand; Port Kembla, Australia; North Star, US) account for 92 per cent of our total Scope 1 and 2 GHG emissions.

Non-steelmaking (midstream and downstream activities) account for the remaining 8 per cent of our GHG emissions profile.

Enablers of steel decarbonisation

We acknowledge that achieving our 2050 net zero goal is highly dependent on several enablers including:

Firmed, affordable renewables

Access to internationally cost-competitive, firmed large-scale renewable energy.

Technology evolution

Development and diffusion of ironmaking technologies to viable and commercial scale.

Hydrogen and natural gas availability

Availability of competitively priced green hydrogen, with natural gas enabling the transition to green hydrogen.

Raw materials supply

Access to appropriate quality and sufficient quantities of economic raw materials.

Public policy

Supportive and consistent policies across all these enablers to underpin decarbonisation.

While technology continues to be a strong area of focus, we understand that technology alone will not deliver the desired transition towards low or zero emissions iron and steelmaking; our approaches must also prioritise progress on the remaining key enablers. 

 

Our focus on reducing steelmaking emissions

A major priority in our approaches to climate action is a focus on our steelmaking activities at PKSW in Australia, Glenbrook in New Zealand, and North Star in North America, given they together constitute 92 percent of our Scope 1 and 2 emissions. In developing our decarbonisation pathway, we must consider the five key enablers within the local business and operating context for each of these three steelmaking sites.

As the following case studies showcase, because the three sites have different contexts, our decarbonisation approach differs for each. 

Our performance in reducing steelmaking emissions 

In 2018, BlueScope set a mid-term target to reduce emissions intensity across our steelmaking plants by 12 per cent by 2030. In FY2024, BlueScope reported a 12.0 per cent reduction in aggregated steelmaking emissions intensity against our FY2018 baseline (1.639 down to 1.443 tCO2e per tonne crude steel), which aligns with our 2030 target.

This was primarily driven by the ramp-up of the North Star expansion, which contributed to an increased proportion of BlueScope’s production volumes coming from North Star’s low emissions process. Further incremental operating and process efficiencies at Glenbrook and Port Kembla also contributed to this outcome.

Looking ahead, all BlueScope steelmaking facilities will continue to focus on improving emissions intensity performance through ongoing process efficiencies and major projects, including the 2025/26 commissioning and ramp-up of the EAF in New Zealand, the debottlenecking project at North Star, and Port Kembla's work program to reline and upgrade its #6 blast furnace and explore low emissions technology options. For more detail on emission trends for our three steelmaking plants and approaches to lowering steelmaking emissions, see our second Climate Action Report.

Notes 1 & 2: In FY2024, historical, baseline and target data were updated. See footnotes 1 & 2 on page 15 - Climate Action Report.