Steel Industry CO₂ Emissions by Process Step

Steel Industry Emissions of CO₂

The main process steps that generate carbon dioxide in iron and steelmaking are the production of coke, and the production of hot metal in the blast furnace. Ancillary facilities such as power plants also produce large volumes of CO₂. The table below identifies typical CO₂ production volumes per tonne of output for each steelmaking process stage.

Figures shown are for typical steel plants in the European Union. Source: European Commission - JRC Scientific and Policy Reports 'Prospective Scenarios on Energy Efficiency and CO₂ Emissions in the EU Iron and Steel Industry', 2012 publication, see table 2, page 13.

Direct emissions from integrated BOF plants typically amount to 1.8–3.0 tonnes CO₂ per tonne of steel produced. DRI-based EAF plants emit approx. 2–3 tonnes CO₂ per tonne of steel if they are coal based, or 0.7–1.2 t/t of steel if they are gas-based. Emissions from scrap based EAF plants are mostly indirect – the CO₂ emissions are not produced by the steel plant, but by the electricity generators that supply electricity to the furnaces.

For a typical EAF, direct emissions are usually around 0.06–0.1 t/t; indirect emissions can add a further 0.4 t/t CO₂. For discussion, see Review on the Use of Alternative Carbon Sources in EAF Steelmaking, Fig 1.

According to the World Steel Association, average greenhouse gas emissions per tonne of worldwide crude steel output stand at ~1.8 t/t [see worldsteel indicators report].