A system and method of direct reduction of iron (DRI) is disclosed, having a reduction unit configured to reduce iron oxides to metallic iron; a process gas heater coupled to the reduction unit, the process gas heater configured to supply the reduction unit directly with a source of heated reducing gas, where the process gas heater is further configured to receive a synthetic combustion air stream for heating the reducing gas, the synthetic combustion air stream comprising a source of oxygen with essentially no nitrogen. A method of carbon dioxide emission reduction from a direct reduction of iron (DRI) process is also disclosed.

A process for the production of direct reduced iron (DRI), with or without carbon, using hydrogen, where the hydrogen is produced utilizing water generated internally from the process. The process is characterized by containing either one or two gas loops, one for affecting the reduction of the oxide and another for affecting the carburization of the DRI. The primary loop responsible for reduction recirculates used gas from the shaft furnace in a loop including a dry dedusting step, an oxygen removal step to generate the hydrogen, and a connection to the shaft furnace for reduction. In the absence of a second loop, this loop, in conjunction with natural gas addition, can be used to deposit carbon. A secondary carburizing loop installed downstream of the shaft furnace can more finely control carbon addition. This loop includes a reactor vessel, a dedusting step, and a gas separation unit.

A process for the production of direct reduced iron (DRI), with or without carbon, using hydrogen, where the hydrogen is produced utilizing water generated internally from the process. The process is characterized by containing either one or two gas loops, one for affecting the reduction of the oxide and another for affecting the carburization of the DRI. The primary loop responsible for reduction recirculates used gas from the shaft furnace in a loop including a dry dedusting step, an oxygen removal step to generate the hydrogen, and a connection to the shaft furnace for reduction. In the absence of a second loop, this loop, in conjunction with natural gas addition, can be used to deposit carbon. A secondary carburizing loop installed downstream of the shaft furnace can more finely control carbon addition. This loop includes a reactor vessel, a dedusting step, and a gas separation unit.

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.

Provision of a gas production apparatus that can stably produce a product gas with carbon monoxide as its main component from a separated gas including carbon dioxide as a main component.

The gas production apparatus 1 consists of the following: a separation and capture section 5, which separates and captures separated gas containing mainly of carbon dioxide from the exhaust gas taken from the line of the exhaust gas equipment; a reaction section 4 including at least a reactor, which is connected to downstream of the separation and capture section 5, contains a reducing agent that generates carbon monoxide through a reduction reaction of carbon dioxide brought into contact with the separated gas, and is capable of separating at least some of oxygen atoms separated from carbon dioxide; a pressure regulating section 7 connected to downstream of the reactor 4 to regulate the pressure of the separated gas supplied to the reactor; and the flow regulating section 6 connected on the upstream of the separation and capture section 5 and regulates the flow rate of the separated gas supplied to the reactor.

A process for the production of direct reduced iron (DRI), with or without carbon, using hydrogen, where the hydrogen is produced utilizing water generated internally from the process. The process is characterized by containing either one or two gas loops, one for affecting the reduction of the oxide and another for affecting the carburization of the DRI. The primary loop responsible for reduction recirculates used gas from the shaft furnace in a loop including a dry dedusting step, an oxygen removal step to generate the hydrogen, and a connection to the shaft furnace for reduction. In the absence of a second loop, this loop, in conjunction with natural gas addition, can be used to deposit carbon. A secondary carburizing loop installed downstream of the shaft furnace can more finely control carbon addition. This loop includes a reactor vessel, a dedusting step, and a gas separation unit.

The disclosure relates to a process for the production of sponge iron from iron ore that includes the steps: charging iron ore into a direct reduction shaft; introducing a hydrogen-rich reducing gas into the direct reduction shaft in order to reduce the iron ore and produce sponge iron; removing a top gas from the direct reduction shaft; dividing the top gas into a recycle stream and a bleed-off stream; processing the bleed-off stream through a separation unit to provide a hydrogen-enriched off-stream and an inert-enriched off-stream; and introducing the recycle stream and the hydrogen-enriched off-stream as constituent parts of the hydrogen-rich reducing gas to the direct reduction shaft. The disclosure further relates to a system for the production of sponge iron.

Systems and processes to produce direct reduced iron with a gaseous reducing stream having less than 10 mol. % nitrogen (N.sub.2) and greater than 80 mol. % methane (CH.sub.4) are described. A process includes separating N.sub.2 from a gaseous stream to produce the reducing stream and contacting the reducing stream with iron ore under conditions sufficient to form direct-reduced iron. The reduction in the N.sub.2 content of the reducing stream improves the overall steel producing capacity by at least 2%.

A system for the production of sponge iron, the system including a direct reduction shaft including a first inlet for introduction of iron ore into the shaft, a first outlet for removing sponge iron from the shaft, a reduction gas source, connected through a gas line with the shaft, a first compressor in said gas line, and a primary circuit for conducting at least a part of the top gas therethrough. The primary circuit is connected in one end with shaft and in another end with said gas line downstream said first compressor. The system also includes a secondary circuit for conducting at least a portion of gas removed from gas conducted through the primary circuit, said secondary circuit being connected in one end to the primary circuit and in another end to said gas line upstream said first compressor. The system further includes means therein for reducing the pressure of said portion of gas conducted through the secondary circuit, and a first valve for controlling a flow of said portion of gas into the secondary circuit.

A system for the production of sponge iron, including a direct reduction shaft, a reduction gas source, a reduction gas container, a primary circuit for conducting at least a part of a top gas therethrough, a secondary circuit for conducting at least a portion of gas removed from gas conducted through the primary circuit, said secondary circuit being connected in one end to the primary circuit and in another end to the reduction gas container, a second gas line connecting the reduction gas source with the reduction gas container, and a third gas line connecting the reduction gas container with the first gas line. The system also includes a control unit configured to control a flow of reduction gas from reduction gas source to the first gas line and to control a flow of reduction gas from the reduction gas container to the first gas line through the third gas line, wherein the control unit is configured to enable a flow of reduction gas from the reduction gas container to said first gas line while correspondingly reducing a flow rate of reduction gas from the reduction gas source to said first gas line.