PROCESS FOR PRODUCING DIRECT REDUCED IRON (DRI) WITH LESS CO2 EMISSIONS TO THE ATMOSPHERE

摘要

A process for producing direct reduced iron (DRI) with lower emissions of CO2 to the atmosphere, in a direct reduction system comprising a direct reduction reactor to which iron oxides are fed in the form of pellets, lumps or mixtures thereof, wherein said iron oxides are caused to react with a reducing gas mainly composed of hydrogen and carbon monoxide at high temperature, and wherein said reducing gas is derived from the reformation of a hydrocarbon-containing gas, and wherein a first portion of the reducing gas stream effluent from said reduction reactor, which contains H2, CO, CO2 and H2O in various proportions, and which is cooled and cleaned in a cooler and which is combined with a gas containing hydrocarbons and said mixture passes through a catalytic reformer before being fed at high temperature to said reduction reactor. CO2 is removed from a portion of the gas stream effluent from said reduction reactor and the resultant gas stream is used as fuel in the reformer thus decreasing the amount of CO2 emitted to the atmosphere. The gas stream containing less CO2 but still containing CO to be used as fuel may further be reacted with water in a "shifter" reactor for converting said CO and H2O to CO2 and H2. In this way more CO2 may be removed from the fuel gas stream and therefore, the resultant fuel gas is mainly composed of hydrogen, further decreasing the amount of CO2 emitted to the atmosphere.