A perspective on the decarbonization of the metals industry

• Metals industry is responsible for a large amount of carbon dioxide emissions and several approaches are in place for limiting the emissions intensity. • Carbon emissions are produced because carbon-bearing species are used either as a reductant or as a fuel in current metals processing routes. • Shifting to alternative technologies that apply carbon-neutral sources, green hydrogen, increased electrification, or even implementing carbon capture are the promising levers to make the metals production activities compatible with the 1.5 °C Paris-consistent trajectory. The decarbonization of the metals industry is a major challenge for the energy transition. Metals are indeed essential elements in the expansion of renewable energy installations worldwide, but they also represent a relevant source of carbon emissions. Therefore, metals producers need to carefully shift their technologies towards less carbon intensive routes. After ranking all the metals in terms of world production volume and total estimated carbon emissions, the three most relevant ones have been selected: steel, aluminum and chromium. Concentrating the rest of the analysis on them, several production processes are available for implementing the decarbonization step, but none of them is currently capable of overcoming the challenge alone and being compatible with the 1.5 °C trajectory. In this perspective, the main production routes are reviewed and proper combinations of proven or emerging technologies are streamlined with the aim to provide an industrially feasible approach to curb the carbon emissions from the metals industry.