Method and device for reducing iron-oxide-containing feedstocks in a high-pressure reducing unit

Abstract

A method for reducing iron-oxide-containing feedstocks by introducing a reducing gas into a high-pressure reducing unit ( 1 ) where the reducing gas is consumed by reducing iron-oxide-containing feedstocks and then the reducing gas is withdrawn as top gas from the high-pressure reducing unit ( 1 ). At least one subportion of the top gas is admixed to a feed gas as recycle gas ( 15 ). The reducing gas is generated by CO 2 being separated off from the gas mixture obtained from the addition of the recycle gas ( 15 ) to the feed gas after one or more compression steps. The recycle gas ( 15 ) is added to the feed gas in at least two recycle gas substreams that are separated from one another with recycle gas substream pressures at various distances from the high-pressure reducing unit ( 1 ).

What is claimed is: 
     
         1 . A facility for reduction of raw materials containing iron oxide, comprising:
 a high-pressure reduction unit, a reduction gas line connected for supplying reduction gas into the high-pressure reduction unit, a top gas line connected for drawing off top gas from the high-pressure reduction unit;   a feed gas line having compression devices arranged therein connected for supplying feed gas or a gas mixture consisting of feed gas and recycle gas, and the feed gas line emerges into a device for separation of CO 2 ,   compression devices disposed in the feed gas line;   at least two recycle gas part flow lines which emerge into different longitudinal sections of the feed gas line are connected for supplying the drawn-off top gas into the feed gas line, wherein a first recycle gas part flow line emerges into the feed gas line in front of a first of the compression devices and a second recycle gas part flow line emerges into the feed gas line after the first of the compression devices; and   devices disposed in the recycle gas part flow lines configured and operable for influencing the size of the respective recycle gas part flow and/or the recycle gas part flow pressure; and   the longitudinal sections of the feed gas line are separated from one another by the compression devices disposed in the feed gas line.   
     
     
         2 . The facility as claimed in  claim 1 , further comprising a DR export gas line connected for drawing off DR export gas from the facility; and
 a device disposed in the DR export gas line for regulating the pressure of the reduction gas and/or of the drawn-off top gas.   
     
     
         3 . The facility as claimed in  claim 1 , further comprising a compression device in at least one of the recycle gas part flow lines and configured for compressing the recycle gas part flow and is connected in parallel in flow technology terms with the device for influencing the size of the respective recycle gas part flow and/or of the recycle gas part flow pressure. 
     
     
         4 . The facility as claimed in  claim 1 , further comprising three of the recycle gas part flow lines emerging into different longitudinal sections of the feed gas line for supplying the drawn-off top gas into the feed gas line. 
     
     
         5 . The facility as claimed in  claim 1 , further comprising a cleaning device configured for cleaning the top gas and/or a device for exchange of heat is disposed in the top gas line. 
     
     
         6 . The facility as claimed in  claim 1 , further comprising the device for separation of CO 2  comprises a PSA facility, or a VPSA facility, or a device for separation of gas mixtures by means of membrane technology and/or chemical reaction.