Method and apparatus for direct reduction ironmaking

1. An apparatus of producing a reducing gas to be supplied to a direct reduction iron-making furnace, comprising:

an internal-heating reformer for reforming a natural gas by adding steam and oxygen to the natural gas to supply a mixture of the natural gas, the steam and the oxygen to a catalyst bed in the reformer and by proceeding both an endothermic reaction of a reformation with steam and an exothermic reaction of partial oxidation in the catalyst bed to generate a reducing gas containing hydrogen and carbon monoxide and having a temperature range between 900 and 1,100° C.;

a carbon dioxide remover for removing carbon dioxide from exhaust gas discharged in the direct reduction iron-making furnace;

an exhaust-gas recycling line for recycling as the reducing gas the exhaust gas from which the carbon dioxide is removed by the remover;

a heat exchanger for increasing a temperature of the carbon dioxide-removed gas to a range between 400 and 700° C. with the exhaust gas discharged in the direct reduction iron-making furnace before recycling the carbon dioxide-removed gas as the reducing gas for the direct reduction iron-making furnace; and

a line for supplying the exhaust gas discharged from the direct reduction iron-making furnace to the heat exchanger before supplying it to the carbon dioxide remover.

2. A method for producing direct reduced iron from a raw material containing iron oxide, comprising the steps of:

reforming a natural gas by supplying the natural gas, steam and oxygen to a catalyst bed in a reformer and by proceeding both an endothermic reaction of a reformation with steam and an exothermic reaction of partial oxidation in the catalyst bed to generate a reducing gas containing hydrogen and carbon monoxide and having a temperature range between 900 and 1,100° C.;

reducing the raw material containing iron oxide in a direct reduction iron-making furnace by using the reducing gas to produce the direct reduced iron;

removing carbon dioxide from exhaust gas discharged from the direct reduction iron-making furnace in the reducing step;

increasing a temperature of the carbon dioxide-removed gas obtained in the removing step to a range between 400 and 700° C. in a heat exchanger;

supplying the exhaust gas discharged from the direct reduction iron-making furnace in the reducing step to the heat exchanger for the increasing step, before subjecting it to the removing step; and

supplying the temperature-increased gas obtained in the increasing step with the reducing gas obtained in the reforming step to the direct reduction iron-making furnace for the reducing step.