Electrochemistry in Action: Iron and Steel Manufacturing

Steel is one of the most manufactured materials in modern society, with 1.9 billion metric tons produced annually for use in building materials, vehicles, wind-turbines, and appliances, among many other applications. As you might expect for something so ubiquitous, the technology used to manufacture steel is also quite mature, having been first identified over 4,000 years ago and heavily industrialized in the 19th century. The general approach is to mine iron ore from the earth’s crust and refine that ore to metallic iron (i.e., ironmaking) which is then combined with carbon and other elements to make steel products (i.e., steelmaking). However, conventional steel manufacturing relies primarily on carbon-based fuels, such as coal, to create the high temperatures (≈ 1600°C) required for the process and can emit as much as 2.2 tons of CO2 per ton of crude steel produced.1 The iron ore reduction step accounts for 90% of CO2 emissions associated with steel production. The heightened effort to decarbonize industrial process and reverse climate change is putting pressure on this 600+ year-old technology to shift to lowcarbon alternatives, especially considering that the steel industry is responsible for ≈ 7% of all global CO2 emissions annually.