System and method for producing steel

A steel production system comprising:

• a first gas generating section comprising a combustion furnace,
• wherein the combustion furnace is configured to burn a gas containing carbon dioxide and carbon monoxide to obtain a first gas by converting the carbon monoxide in the gas to carbon dioxide;
• a deoxidization device configured to remove oxygen contained in the first gas;
• a reducing gas supply section configured to supply a reducing gas containing a reducing substance,
• wherein the reducing substance reduces a reducing agent that contains a metal oxide,
• wherein the metal oxide reduces carbon dioxide and is oxidized by contact with the carbon dioxide;
• a reaction section including a plurality of reactors that are respectively connected to at least one of the deoxidization device and the reducing gas supply section,
• wherein the reducing agent is arranged in each of the plurality of reactors,
• wherein the reaction section is capable of switching between the first gas from which the oxygen has been removed and the reducing gas supplied to each of the plurality of reactors or capable of transferring the reducing agent between the plurality of reactors;
• a compression section configured to increase pressure of the first gas from which the oxygen has been removed before being supplied to the plurality of reactors;
• and
• a return line configured to supply a second gas from the reaction section to a melting furnace, the second gas being obtained by contacting the first gas from which the oxygen has been removed supplied to the plurality of reactors with the reducing agent to convert the carbon dioxide to carbon monoxide and the second gas having the carbon monoxide as a main component.