Method and system for the production of porous iron

Abstract

Described are a method and a system for producing porous iron by means of a direct reduction process. In said method and system, a reducing gas is introduced into a DRI reduction device, and the direct reduction process is carried out therein. Coke oven gas and/or natural gas is/are reformed by adding gas, which contains steam and carbon dioxide and which is top gas from a DRI reduction device, and oxygen in a COG reformer so as to obtain reducing gas.

1 . Method for the production of porous iron via a direct reduction process in which the reducing gas is introduced into the DRI reduction device and in which the direct reduction process is carried out, identified by the coke oven gas and/or natural gas by the addition of water vapor and carbon dioxide gas, which is top gas from a DRI reduction device ( 5 ), and from the oxygen in a COG reformer ( 1 ) is reformed to the reducing gas. 
     
     
         2 . Method according to  claim 1 , characterized in that the reducing gas is partially produced in the COG reformer ( 1 ) from the coke oven gas and/or natural gas and partly from the top gas of the same DRI reduction device ( 5 ). 
     
     
         3 . Method according to  claim 2 , characterized in that the reducing gas is produced in approximately equal parts from the outlet gas of the COG reformer ( 1 ) and from the top gas of the reduction device ( 5 ). 
     
     
         4 . Method according to one of the preceding claims, characterized in that the coke oven gas and/or natural gas is mixed with water vapor and carbon dioxide containing gas and the resulting gas mixture and oxygen are introduced into the COG reformer ( 1 ). 
     
     
         5 . Method according to  claim 4 , characterized in that the obtained gas mixture and oxygen in the lower region of the COG reformer ( 1 ) and a subset of the oxygen in the central region of the COG reformer ( 1 ) are introduced. 
     
     
         6 . Method according to one of the preceding claims, characterized in that the outlet gas of the COG reformer ( 1 ) is supplied to a subset of coke oven gas and/or natural gas. 
     
     
         7 . Method according to one of  claims 4  to  6 , characterized in that the gas mixture of coke oven gas and/or natural gas, the water vapor and carbon dioxide containing gas is heated prior to introduction into the COG reformer ( 1 ), wherein its temperature becomes adjusted depending on the methane content. 
     
     
         8 . Method according to one of the preceding claims, characterized in that at least one double lance ( 10 ) is used to introduce the gas mixture from the coke oven gas and/or natural gas as well as the water vapor, the carbon dioxide gas and oxygen, wherein the oxygen via the inner lance tube and the space between the inner tube and outer tube, the gas mixture in the COG reformer ( 1 ) are introduced. 
     
     
         9 . System for the production of porous iron, in particular for carrying out the process according to one of  claims 1  to  8 , with a DRI reduction device, characterized in that it further comprises a COG reformer ( 1 ) in which the coke oven gas and/or the natural gas, water vapor and carbon dioxide-containing gas, which is top gas from a DRI reduction device ( 5 ) and oxygen is reformed to the reducing gas, is provided. 
     
     
         10 . System according to  claim 9 , characterized in that in comprises a device for discharging and processing the top gas of the DRI reduction device ( 5 ) to the reducing gas and for supplying the same reduction device together with the reducing gas from the COG reformer.( 1 ). 
     
     
         11 . System according to  claims 9  to  10 , characterized in that it comprises means for mixing the coke oven gas and the natural gas with the water vapor and carbon dioxide containing gas prior to introduction into the COG reformer ( 1 ). 
     
     
         12 . System according to  claim 11 , characterized in that it comprises the means for introducing the obtained gas mixture and oxygen into the lower region of the COG reformer ( 1 ) and the means for introducing oxygen into the middle part of the COG reformer ( 1 ). 
     
     
         13 . System according to one of  claims 9  to  12 , characterized in that it comprises the means for supplying a subset of coke oven gas and/or natural gas to the outlet gas of the COG reformer ( 1 ). 
     
     
         14 . System according to one of  claims 9  to  13 , characterized in that it has a device for heating the water vapor and the carbon containing gas, prior to introduction into the COG reformer ( 1 ). 
     
     
         15 . System according to one of  claims 12  to  14 , characterized in that it comprises at least one double lance ( 10 ) for introducing the gas mixture and oxygen in the COG reformer ( 1 ). 
     
     
         16 . System according to  claim 15 , characterized in that the double lance ( 10 ) designed as a double tube has a water-cooled inner tube enveloped by a protective tube.