Going net zero for cement and steel

The chemical reactions involved give off CO2, as does burning fossil fuels to deliver the extreme temperatures required in the manufacturing processes. Coke (derived from coal) fuels blast furnaces in which iron ores are chemically reduced to metallic iron at temperatures of up to2,300 °C. Coke burns to produce carbon monoxide, which reduces the ore to iron and CO2. About 5% of the world's steel is already made through 'direct reduced iron' (DRI) processes that don't require coke and typically use hydrogen and CO (derived from methane or coal). Tata Steel, based in Jamshedpur, India, built a pilot plant in 2010 in the Netherlands for one advanced steel-making process, still based on coal but simplified to make carbon capture easier.