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 H.sub.2O and CO.sub.2 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.

A method for producing direct reduced iron having increased carbon content, comprising: providing a carbon monoxide-rich gas stream; and delivering the carbon-monoxide-rich gas stream to a direct reduction furnace and exposing partially or completely reduced iron oxide to the carbon monoxide-rich gas stream to increase the carbon content of resulting direct reduced iron. The carbon monoxide-rich gas stream is delivered to one or more of a transition zone and a cooling zone of the direct reduction furnace. Optionally, providing the carbon monoxide-rich gas stream comprises initially providing one of a reformed gas stream from a reformer and a syngas stream from a syngas source. Optionally, the carbon monoxide-rich gas stream is derived, at least in part, from a carbon monoxide recovery unit that forms the carbon monoxide-rich gas stream and an effluent gas stream. Optionally, the method still further includes providing a hydrocarbon-rich gas stream to one or more of a transition zone and a cooling zone of the direct reduction furnace, with and/or separate from the carbon monoxide-rich gas stream.

Disclosed is a method of operating a furnace containing a charge to heat the charge, comprising wherein gaseous oxidant comprising 60 vol. % to 85 vol. % oxygen is passed through a heated regenerator and into the furnace, so that the oxidant is heated to emerge from an oxidant port at a temperature of 500 C. to 1400 C., and gaseous fuel is fed into said furnace through two or more fuel ports; and the heated oxidant and fuel are combusted in the furnace to produce gaseous hot products of said combustion which heat the charge; and then the flow of oxidant through the regenerator into the furnace is discontinued, and said combustion products are passed into said oxidant port and through and out of said cooled regenerator to heat said regenerator, wherein the temperature of the combustion products that pass out of said regenerator is at least 500 C.; under dimensional and operational conditions which attain functional and economic advantages.

A process for processing metal ore includes: reducing a metal ore, particularly a metallic oxide, in a blast furnace shaft; producing furnace gas containing CO.sub.2, in the blast furnace shaft; discharging the furnace gas from the blast furnace shaft; directing at least a portion of the furnace gas directly or indirectly into a CO.sub.2-converter; and converting the CO.sub.2 contained in the furnace gas into an aerosol consisting of a carrier gas and C-particles in the CO.sub.2-converter in the presence of a stoichiometric surplus of C; directing at least a first portion of the aerosol from the CO.sub.2-converter into the blast furnace shaft; and introducing H.sub.2O into the blast furnace shaft. By virtue of the reaction C+H.sub.2O.fwdarw.CO.sub.2+2H, nascent hydrogen is produced in the blast furnace which causes rapid reduction of the metal ore. The speed of reduction of the metal ore is thus increased, and it is possible to increase either the throughput capacity of the blast furnace or to reduce the size of the blast furnace. An aerosol in the form of a fluid is easily introducible into the blast furnace shaft.

Method of operating a blast furnace installation comprising a top gas recycle blast furnace and hot stones, whereby a hydrocarbon containing fuel is transformed into a transformed gas stream consisting mainly of CO and H.sub.2 and substantially devoid of hydrocarbon, whereby a low-heating-value gaseous fuel is generated comprising a mixture of said transformed gas with a portion of the CO.sub.2-rich tail gas obtained by decarbonatation of the blast furnace gas, and whereby said low-heating-value fuel is used to heat the hot furnace gas is heated before being injected into the blast-furnace.

A system for energy optimization in a plant (3) for producing direct-reduced metal ores (3). The plant (3) has at least one reduction unit (12), a device for separating gas mixtures (7, 7a, 7b) having an associated compressing device (4, 4a, 4b), and a gas-heating device (10) upstream of the reduction unit (12). Part of the process gases (2, 2a, 2b) is fed by a feed line from a smelting reduction plant to the plant for producing direct-reduced metal ores (3). A turbine (8, 8a, 8b) is fit between the device for separating gas mixtures (7, 7a, 7b) and the gas-heating device (10) upstream of the reduction unit (12) such that a pressure drop between the device for separating gas mixtures (7, 7a, 7b) and the reduction unit (12) is converted into forms of energy that can be used to operate additional components (4, 4a, 4b, 15, 15a, 15b) of the plant (3), in particular electrical energy and/or mechanical energy. Energy consumption of the plant (3) is reduced.

Methods and systems for producing direct reduced iron (DRI), comprising: generating a syngas stream in a carbon dioxide (CO2) and steam reformer; and providing the syngas stream to a direct reduction (DR) shaft furnace as a reducing gas stream. The methods and systems also comprise combining the syngas stream with a recycled off-gas stream from the DR shaft furnace to form the reducing gas stream. The methods and systems further comprise removing carbon dioxide (CO2) from the recycled off-gas stream from the DR shaft furnace prior to combining it with the syngas stream to form the reducing gas stream. The methods and systems still further comprise feeding CO2 removed from the recycled off-gas stream from the DR shaft furnace to the CO2 and steam reformer. The methods and systems still further comprise feeding recycled off-gas from the recycled off-gas stream from the DR shaft furnace to the CO2 and steam reformer.

Provided is a method of operating a blast furnace, including generating a regenerative methane gas using a blast furnace by-product gas, and blowing a blast gas and a reducing agent into the blast furnace from a tuyere, in which the blast gas is oxygen gas, the regenerative methane gas is used as at least part of the reducing agent, and the oxygen gas and/or the regenerative methane gas is preheated before being blown into the blast furnace from the tuyere.

A direct reduction system for a direct reduction of iron ore, comprising a reactor having a reduction area and being adapted to be loaded from above with said iron ore; a treatment and feeding line, to process the process gases, thus obtaining a reducing gas mixture, and feed said reducing gas mixture into the reduction area; a line for recovering and treating an exhausted gas exiting the reactor, communicating upstream with the reactor and downstream with said treatment and feeding line; wherein at least one bypass duct is provided, adapted to divert at least one portion of reducing gas mixture from said treatment and feeding line to said recovery and treatment line.

A release apparatus for receiving an ocean alkalinity product from an Ocean Alkalinity Enhancement (OAE) system (or other alkalinity source), and for releasing the alkalinity into an ocean at a maximum safe delivery rate to facilitate atmospheric CO.sub.2 reduction and mitigate ocean acidification. The release apparatus includes a diffuser having a plenum chamber defining exit ports, a flow control mechanism that controls delivery of the ocean alkalinity product through the exit port(s) into an outfall region (i.e., an ocean region surrounding the diffuser), sensors for measuring seawater parameters in the outfall region, and a controller configured to control an operating (actuation) state of the flow control device (e.g., by way of generating and transmitting a flow control signal) in accordance with the measured seawater parameters). The plenum chamber is anchored at an outfall location and is maintained at a constant depth with the exit ports aimed toward the ocean surface.