"In blast furnace steel manufacturing, coke (a type of coal) is used to produce metallic iron from ore obtained from mining — which releases large quantities of carbon dioxide in the process. According to Dr Harriet Kildahl, who co-devised the method with Professor Yulong Ding, their technology aims to convert this carbon dioxide into carbon monoxide that can be reused in the iron ore reaction.

Damaging CO2 is turned into a useful part of the reaction, forming “an almost perfect closed carbon loop.” This drastically reduces emission by the amount of coke needed and, subsequently, lowers steelmaking’s emissions by up to 88%." 

Uk-scientists-discover-method-reduce-steelmakings-co2-emissions

full study: science article

"This research presents the first-principles calculations of the coupling of a thermochemical cycle with a BF-BOF to cheaply decarbonise the steel sector. Decarbonisation can be achieved by replacing 90% of typical coke use with carbon monoxide, produced from carbon dioxide."