With a share of up to 6 % of anthropogenic CO2 emissions, the metal and steel industry is one of the largest emitters of CO2 globally. Especially the production of steel, where fossil feedstocks are used to chemically bind the iron ores' oxygen to obtain iron or steel, is in dire need of low-carbon future-proof technologies. While such schemes were proposed, literature data is inconsistent regarding the assumptions and boundary conditions. A large scale of necessary investments, complex supply chains, and long planning periods are required for a successful realization of decarbonization....