Method for heating process gases for direct reduction systems

Abstract

A method for reducing iron ore in the direct reduction method, in which the iron ore to be reduced is conveyed through a reduction unit such as a reduction shaft and is brought into contact with a reduction gas; the reduction gas is brought into the reduction unit and flows through the unit; after flowing through the unit, it is taken from the unit; after exiting the unit, the gas is prepared and possibly enriched with new gas components and is fed back again; and the generated gas is heated before entry into the reduction unit, characterized in that the heating of the reduction gas prior to the entry into the unit is carried out in an electrical fashion.

1 . A method for reducing iron ore in a direct reduction method, comprising:
 conveying the iron ore to be reduced through a reduction unit such as a reduction shaft and bringing the iron ore into contact with a reduction gas;   bringing the reduction gas into the reduction unit to flow through the unit;   after flowing through the unit, taking the reduction gas from the unit;   after exiting the unit, preparing the gas and possibly enriching the gas with new gas components and feeding the gas back again into the reduction unit; and   heating the generated gas mixture or the reduction gas products from the generated gas mixture to 700 to 1100 before entry into the reduction unit, wherein the heating is carried out in a predominantly electrical fashion.   
     
     
         2 . The method according to  claim 1 , comprising using electrical power from regenerative energy sources for the electric heating. 
     
     
         3 . The method according to  claim 1 , further comprising, after the gas has exited the unit, enriching the gas with natural gas, coke oven gas, or a synthesis gas from biomass or coal. 
     
     
         4 . The method according to  claim 1 , comprising enriching the gas mixture with oxygen. 
     
     
         5 . The method according to  claim 1 , comprising enriching the gas taken from the reduction shaft with natural gas, coke oven gas, or a synthesis gas from biomass or coal and then heating the enriched gas. 
     
     
         6 . The method according to  claim 1 , comprising enriching the gas taken from the reduction shaft with natural gas, coke oven gas, or a synthesis gas from biomass or coal and then transforming the enriched gas in a reformer. 
     
     
         7 . The method according to  claim 1 , comprising ensuring a cost-optimized use of energy sources through a continuous evaluation of gas prices and electricity prices.