Abstract: Methods and systems for producing steel or similar molten-iron-containing materials in melting or smelting furnaces utilizing pre-reduced iron ore, known also as direct reduced iron (DRI) or sponge iron, wherein the emission of CO2 and other greenhouse gases is significantly low. Such methods and systems are based on producing DRI in a direct reduction furnace with a reducing gas comprising hydrogen; melting at least a portion of the DRI in a melting furnace in order to generate hot gases; producing steam and/or hot water using the heat contained in the hot gases. From the steam and/or hot water hydrogen is produced by electrolysis, at least a portion of which is fed to the direct reduction furnace as a component of the reducing gas to produce the DRI.

Abstract: The present invention concerns a method and an apparatus for producing DRI (Direct Reduced Iron) utilizing a high-oxidation reducing gas containing carbon monoxide and hydrogen, derived directly or indirectly from the gasification of hydrocarbons or coal, with a high content of oxidants (H2O and CO2). The invention provides a more efficient method and plant comprising a reactor in which particulate material of iron ore comes into contact with a high temperature reducing gas to produce DRI, with lower investment and operating costs, avoiding the need for a fired heater for the reducing gas fed into the reduction reactor. The reducing gas is heated to a temperature above 700° C. in two steps, a first step at a temperature below about 400° C.

Abstract: A blast furnace where coke is combusted with oxygen, instead of air, and where a top gas comprising CO, CO2, H2, and without excess nitrogen is withdrawn from the upper part of the blast furnace, cleaned of dust, the H2/CO volume ratio adjusted to between 1.5 to 4.0 in a water shift reactor, water and CO2 are removed (increasing its reduction potential), heated to a temperature above 850° C. and fed back to the blast furnace above where iron starts melting (thereby increasing the amount of metallic iron reaching the dead-man zone and decreasing the amount of coke used for reduction). Also carbon deposit problems caused by heating the CO-containing recycled gas are minimized by on-line cleaning of the heater tubes with steam without significantly affecting the reduction potential of the recycled reducing gas.

Abstract: Production method and apparatus for direct reduced iron (DRI), a.k.a sponge iron, by contacting iron oxides with recycled and regenerated hot reducing gases containing H2 & CO2. This invention decreases uncontained emission of CO2 to the atmosphere from combustion of carbon-bearing fuels in the reducing-gas heater by substituting, at least partially, a gas mainly comprising hydrogen in lieu of the usual carbon-bearing fuels. The hydrogen fuel stream, depleted of CO2 by means of a physical gas separation unit (which can be a PSA/VPSA type adsorption unit, a gas separation membrane unit or a combination of both such units) is derived from at least a portion of regenerated reducing gases being recycled to the reduction reactor. The derived hydrogen fuel stream is combusted in the reducing gas heater and/or other thermal equipment in the reduction plant, thus decreasing the CO2 emissions directly to the atmosphere.

Abstract: The present invention concerns a method and an apparatus for producing DRI (Direct Reduced Iron) utilizing a high-oxidation reducing gas containing carbon monoxide and hydrogen, derived directly or indirectly from the gasification of hydrocarbons or coal, with a high content of oxidants (H2O and CO2). The invention provides a more efficient method and plant comprising a reactor in which particulate material of iron ore comes into contact with a high temperature reducing gas to produce DRI, with lower investment and operating costs, avoiding the need for a fired heater for the reducing gas fed into the reduction reactor. The reducing gas is heated to a temperature above 700° C. in two steps, a first step at a temperature below about 400° C.

Abstract: A process for reducing iron ore particles in a moving bed reduction reactor comprising an upper reduction zone and a lower discharge zone, wherein coke oven gas, preferably forming all the make-up for the reducing gas circulating through and reacting in the reduction zone, is first fed to the discharge (and, optionally, cooling) zone and thereafter, conditioned by the DRI in the lower zone, is withdrawn from the reactor and transferred externally into the recycle reducing gas for injection into the reduction zone; with the heavy hydrocarbons and other components of coke oven gas which cause fouling, corrosion, or deposits in the direct reduction plant being removed from coke oven gas by catalytic and/or adsorptive action of the DRI in the lower zone; preferably the gas flow rate of the coke oven gas and the externally transferred gas differs between about 100 and 200 NCM per ton of DRI produced.

Abstract: A method and apparatus for producing direct reduced iron (DRI), also known as sponge iron, by means of direct contact of iron oxides with a stream of recycled and regenerated hot reducing gases containing hydrogen and carbon monoxide. The invention provides a way for decreasing the uncontained emission of CO2 to the atmosphere produced by combustion of carbon-bearing fuels in the reducing gas heater by substituting, at least partially, a gas stream mainly composed of hydrogen in lieu of the usual carbon-bearing fuels. The hydrogen fuel stream, depleted of CO2 by means of a physical gas separation unit (which can be a PSA/VPSA type adsorption unit, a gas separation membrane unit or combination of PSA/VPSA unit and a gas separation membrane unit) is derived from at least a portion of a stream of regenerated reducing gases being recycled to the reduction reactor.

Abstract: A direct reduction plant for the production of a metallized product (DRI) by the reduction of iron ores in lump or pellet form, wherein the reducing gas utilized in the DRI reactor contains acid gases such as sulphur compounds and carbon dioxide. The make-up reducing gases are typically produced by partial oxidation of hydrocarbons (syngas) at a high pressure while the DRI reactor is usually operated at a lower pressure. The pressure level of the reducing gas effluent from the DRI reactor (top gas), after cooling and dewatering, is increased to the pressure level of the syngas and the resulting recycle reducing gas is then combined with the make-up syngas and treated in a single acid-gas absorption unit forming a combined stream of clean upgraded reducing gas which thereafter is expanded in a turbine for lowering combined reducing gas pressure to the pressure level of the DRI reactor and is then heated to a temperature preferably above 950° C. and used in the DRI reactor for producing said DRI.

Abstract: A process for reducing iron ore particles in a moving bed reduction reactor comprising an upper reduction zone and a lower discharge zone, wherein the coke oven gas, preferably forming all the make-up for the reducing gas circulating through and reacting in said reduction zone, is first fed to said discharge (cooling) zone and thereafter said coke oven gas, conditioned by the DRI in the lower zone, is withdrawn from the reactor and fed preferably into the recycled reducing gas for injection into the reduction zone of the reactor. Heavy hydrocarbons and other components of coke oven gas which may otherwise cause fouling, corrosion, or deposits in the direct reduction plant are removed from coke oven gas by catalytic and/or adsorptive action of the DRI present in said lower zone, before being externally transferred to the reduction zone of the reduction reactor.

Abstract: A method and an integrated steel plant wherein, instead of using coke oven gases, converter gases and blast furnace top gases available as fuel for power generation or other heating purposes, these gases are more efficiently utilized as chemical agents for direct reduction of iron ores producing DRI. DRI is charged to blast furnaces increasing production of crude steel without increasing the capacities of the coke oven plant and blast furnaces and without changes in the quality of the crude steel, or, if production rate is maintained, the fossil fuels specific consumption is significantly reduced. Utilisation of primary fossil energy according to the invention also reduces the specific CO2 emissions per ton of crude steel. The specific CO2 emission in conventional integrated mills is about 1.6 tons of CO2 per ton of crude steel.

Abstract: A method and an integrated steel plant wherein, instead of using coke oven gases, converter gases and blast furnace top gases available as fuel for power generation or other heating purposes, these gases are more efficiently utilized as chemical agents for direct reduction of iron ores producing DRI.