Abstract: A method and apparatus for producing direct reduced iron using a pre-treated make-up gas as a reducing agent in a direct reduced iron reactor are provided. The method involves pre-treating a stream of make-up gas containing heavy hydrocarbons by subjecting the stream to low temperature adiabatic reforming at a temperature between 300° C. and 600° C., prior to using the stream of make-up gas as a reducing agent for producing direct reduced iron. The method also involves adjusting the humidity content of the stream of make-up gas after the low temperature adiabatic reforming by bypassing the stream to selectively split it into a first part of the stream of make-up gas and a second part of the stream of make-up gas, subjecting the first part to water separation, and then mixing the first part with the second part to obtain a reducing stream to be sent to direct reduced iron production.

Abstract: Producing direct reduced iron (DRI) having chemically-combined carbon includes providing DRI at a temperature above 400° C., providing a first gas stream including hydrogen and carbon monoxide, passing the first gas stream through a methane forming process to yield a second gas stream containing a higher concentration of methane than the first gas stream; and contacting the second gas stream with the DRI. A system for producing the DRI includes a vessel for containing DRI at a temperature above 400° C., a methane forming reactor containing a catalyst bed for producing methane from a first gas stream containing hydrogen and carbon monoxide, a first conduit to feed a gas stream including hydrogen and carbon monoxide to the methane forming reactor, and a second conduit to feed the second gas stream to the vessel containing the DRI.

Abstract: A method and apparatus for producing direct reduced iron using a pre-treated make-up gas as a reducing agent in a direct reduced iron reactor are provided. The method involves pre-treating a stream of make-up gas containing heavy hydrocarbons by subjecting the stream to low temperature adiabatic reforming at a temperature between 300° C. and 600° C., prior to using the stream of make-up gas as a reducing agent for producing direct reduced iron. The method also involves adjusting the humidity content of the stream of make-up gas after the low temperature adiabatic reforming by bypassing the stream to selectively split it into a first part of the stream of make-up gas and a second part of the stream of make-up gas, subjecting the first part to water separation, and then mixing the first part with the second part to obtain a reducing stream to be sent to direct reduced iron production.

Abstract: Producing direct reduced iron (DRI) having chemically-combined carbon includes providing DRI at a temperature above 400° C., providing a first gas stream including hydrogen and carbon monoxide, passing the first gas stream through a methane forming process to yield a second gas stream containing a higher concentration of methane than the first gas stream; and contacting the second gas stream with the DRI. A system for producing the DRI includes a vessel for containing DRI at a temperature above 400° C., a methane forming reactor containing a catalyst bed for producing methane from a first gas stream containing hydrogen and carbon monoxide, a first conduit to feed a gas stream including hydrogen and carbon monoxide to the methane forming reactor, and a second conduit to feed the second gas stream to the vessel containing the DRI.

Abstract: Direct reduction process and plant for producing DRI comprising a reduction reactor and at least one reducing gas heater typically comprising a convective heating section and a radiant heating section for raising the reducing gas temperature to a level adequate for iron oxides reduction to metallic iron, typically above 850° C., wherein the reducing gas fed to the reduction reactor comprises a stream of reducing gas recycled from the reduction reactor and a make-up stream of coke oven gas containing carbon compounds which may form carbon deposits in the heating path of said heater, namely BTX and other complex carbon compounds. The heater is provided with means for feeding oxidizing agents, for example steam, steam and air and/or oxygen at predetermined heating tubes successively for eliminating the carbon deposits which may form inside the heating tubes of said heater without interrupting the operation of the plant.

Abstract: A process for producing DRI from iron ores, utilizing a gas produced from fossil fuels, containing sulfur compounds and BTX, heating said gas in a heater, preferably a regenerator, wherein heat is transferred from a previously-heated solid material to the gas. Flowing the hot gas through a bed of DRI particles, iron oxides or other equivalent material, outside of the reduction reactor, where said material adsorbs sulfur compounds and destroys BTX. The resulting gas, free from sulfur compounds and BTX, is combined with a reducing gas stream from the reduction reactor after H2O and CO2 is at least partially removed for regenerating its reducing potential, with or without undergoing previous cleaning, is used for producing DRI. One inventive embodiment comprises producing DRI at high temperature giving advantageously higher productivity and energy savings when using hot DRI in an electric arc furnace lowering the capital and operational costs of steelmaking.

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: Direct reduction process and plant for producing DRI comprising a reduction reactor and at least one reducing gas heater typically comprising a convective heating section and a radiant heating section for raising the reducing gas temperature to a level adequate for iron oxides reduction to metallic iron, typically above 850° C., wherein the reducing gas fed to the reduction reactor comprises a stream of reducing gas recycled from the reduction reactor and a make-up stream of coke oven gas containing carbon compounds which may form carbon deposits in the heating path of said heater, namely BTX and other complex carbon compounds. The heater is provided with means for feeding oxidizing agents, for example steam, steam and air and/or oxygen at predetermined heating tubes successively for eliminating the carbon deposits which may form inside the heating tubes of said heater without interrupting the operation of the plant.

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: A process for producing direct reduced iron (DRI) from iron ores, utilizing a gas produced from fossil fuels, particularly coal, containing sulfur compounds and BTX, wherein said gas is heated in a gas heater, preferably of the regenerative type, wherein heat is transferred from a previously-heated solid material to the gas produced from coal. The hot gas is caused to flow through a bed of DRI particles, iron oxides or other equivalent material, outside of the reduction reactor, where said material adsorbs sulfur compounds and the BTX are destroyed. The gas resulting from this treatment, free from sulfur compounds and BTX, is combined with a reducing gas stream withdrawn from the reduction reactor after H2O and CO2 have at least partially have been removed for regenerating its reducing potential, with or without undergoing a previous cleaning treatment, is used for producing 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 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 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 direct reduction process for producing direct reduced iron (DRI) in a reduction reactor having a reduction zone for reducing iron-oxides-containing particles, such as iron ore pellets, to DRI by reaction of said iron oxides with a high temperature reducing gas, and a cooling zone for lowering the temperature of the DRI produced in said reduction zone, wherein a stream of cooling gas, usually natural gas, is circulated through said cooling zone, a portion of said cooling gas is withdrawn from the cooling zone, cooled and cleaned in a gas cooler and a portion of the cooled gas is recycled to said reduction zone by means of an ejector utilizing the high-pressure natural gas make-up feed as the ejector's motive fluid. Using an ejector for recycling the cooling gas instead of using a mechanical compressor provides significant savings in electricity and in capital, operational and maintenance costs.

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 direct reduction process for producing direct reduced iron (DRI) in a reduction reactor having a reduction zone for reducing iron-oxides-containing particles, such as iron ore pellets, to DRI by reaction of said iron oxides with a high temperature reducing gas, and a cooling zone for lowering the temperature of the DRI produced in said reduction zone, wherein a stream of cooling gas, usually natural gas, is circulated through said cooling zone, a portion of said cooling gas is withdrawn from the cooling zone, cooled and cleaned in a gas cooler and a portion of the cooled gas is recycled to said reduction zone by means of an ejector utilizing the high-pressure natural gas make-up feed as the ejector's motive fluid. Using an ejector for recycling the cooling gas instead of using a mechanical compressor provides significant savings in electricity and in capital, operational and maintenance costs.

Abstract: A process and system for producing reducing gases are disclosed, wherein volatile components derived from coal are transformed into reducing gases suitable for utilization as synthesis gas, as a reducing agent for the direct reduction of iron ores and/or as a clean fuel.

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.

Abstract: A process for the gaseous reduction of iron ore to sponge in a vertical shaft, moving bed reactor wherein a hot gaseous mixture of hydrogen and carbon monoxide generated by the internal steam reformation of gaseous hydrocarbon(s), preferably methane or natural gas, is used to reduce the ore without the need for any external catalytic reformer. A reducing gas recycle loop is established to which hydrocarbon and reclaimed waste hot water are fed in the proper proportions as the reducing gas make-up source with the sponge iron produced in the reduction reactor being used to catalyze hydrocarbon reformation, and with the carbon content of the recycled gas being maintained low by removing carbon dioxide therefrom.