Method for producing direct reduced iron with a controlled amount of carbon

A method for producing direct reduced iron with a controlled amount of carbon, in a reduction system without a natural gas reformer and wherein the reducing gas is generated by reformation of the hydrocarbons in the reducing gas with water and oxygen within the reduction system, the method being carried out in a moving bed reduction reactor, having a reduction zone, where iron-oxides-containing particulate materials are, at least partially, chemically reduced to metallic iron by a high-temperature, carbon containing reducing gas comprising hydrogen and carbon monoxide as reducing agents, the method comprising:

• introducing the iron-oxides-containing particulate material into the reduction zone of the reactor;
• feeding to the reduction zone a first stream of reducing gas at a temperature in the range from about 900.degree. C. to about 1150.degree. C., and causing the reducing gas to flow upwardly through the reduction zone to at least partially reduce the iron oxides therein into metallic iron,
• carburizing the metallic iron with carbon from the reducing gases fed into the reactor to produce direct reduced iron;
• withdrawing from the reduction zone a second stream of reducing gas at a temperature in the range from about 250.degree. C. to about 450.degree. C., said second stream containing carbon dioxide and water;
• removing carbon dioxide from a portion of the second stream resulting in a third stream containing no more than about 10% carbon dioxide;
• mixing the third stream with natural gas to form a fourth stream of reducing gas;
• adjusting the water content in the fourth stream to a value in the range from about 5% to about 12% by volume;
• heating the fourth gas stream to a temperature in the range from about 850.degree. C. to about 1000.degree. C.;
• mixing the fourth stream with an oxygen-containing gas;
• raising the temperature of the fourth stream in the range from about 950.degree. C. to about 1150.degree. C. to form the first stream;
• and
• discharging the direct reduced iron from the reactor.