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 hydrogen release and storage system (100) of the present invention includes a first hydrogen release and storage unit (100A) composed of a first hydrogen compound member (101A), a first container (102A) that accommodates the first hydrogen compound member (101A), a first heating apparatus (103A) configured to heat an inside of the first container (102A), a first cooling apparatus (104A) configured to cool the inside of the first container (102A), a first water supply apparatus (105A) configured to supply water to the first container (102A), a second hydrogen release and storage unit (100B) composed of a second hydrogen compound member (101B), a second container (102B) that accommodates the second hydrogen compound member (101B), a second heating apparatus (103B) configured to heat an inside of the second container (102B), a second cooling apparatus (104B) configured to cool the inside of the second container (102B) and a second water supply apparatus (105B) configured to supply water to the second container (102B).

The present disclosure relates to a process for the production of carburized sponge iron. The process comprises the steps of reducing iron ore pellets using a carbon-lean reducing gas in a direct reduction shaft reactor to provide a sponge iron intermediate; transferring the sponge iron intermediate to a carburization unit; and carburizing the sponge iron intermediate in the carburization unit using a carburizing gas to provide carburized sponge iron. The disclosure further relates to a system for the production of carburized sponge iron, a carburized sponge iron produced by the aforementioned process, and a sponge iron intermediate obtained during the production of such a carburized sponge iron.

A hydrogen release and storage system (100) of the present invention includes a hydrogen compound member (101), a container (102) that accommodates the hydrogen compound member (101), a heating apparatus (103) configured to heat the inside of the container (102), a cooling apparatus (104) configured to cool the inside of the container (102) and a water supply apparatus (105) configured to supply water to the container (102).

Provided is a steelmaking line contributing to the realization of a method that achieves energy saving and CO.sub.2 emission reduction when producing reduced iron from iron oxide. The steelmaking line comprises: a blast furnace configured to reduce iron oxide; a reducing furnace configured to reduce iron oxide; a methane synthesizer configured to synthesize methane from blast furnace gas and/or furnace top gas, and hydrogen gas; a blower configured to blow the methane gas synthesized by the methane synthesizer into the blast furnace; a heat-reformer configured to heat or heat-reform the blast furnace gas and/or the furnace top gas, and the methane gas synthesized by the methane synthesizer, to generate reducing gas; a reducing gas blower configured to blow the reducing gas into the reducing furnace; and a supply path configured to supply the furnace top gas to the methane synthesizer and/or the heat-reformer.

Systems for producing iron may include (a) a reactor configured to receive iron ore and a reducing gas, and from these produce iron; and (b) a carbon dioxide reduction electrolyzer configured to produce at least carbon monoxide and/or a hydrocarbon. Such systems may be configured to transport carbon dioxide produced by the reactor and/or produced by combustion of a gas generated by the reactor to a cathode side of the carbon dioxide reduction electrolyzer. Such systems may be further configured to transport at least a portion of the carbon monoxide and/or hydrocarbon produced by the carbon dioxide reduction electrolyzer to the reactor, where the carbon monoxide and/or hydrocarbon serves as at least a part of the reducing gas.

A method for producing reduced iron that produces reduced iron by reducing iron oxide charged in a shaft furnace, in which a gas mixture which contains a reducing gas and a nitrogen gas, and has a predetermined temperature, is blown into the shaft furnace. The reducing gas contains 90 volume% or more of a hydrogen gas.

A method for producing reduced iron that produces reduced iron by reducing iron oxide charged in a shaft furnace, in which a heated gas mixture which contains a reducing gas and a nitrogen gas, the reducing gas containing 90 volume % or more of a hydrogen gas, is blown into the shaft furnace from a tuyere equipped at a lower portion of a reduction zone of the shaft furnace, at least part of the reducing gas is blown into a cooling zone of the reduced iron provided at a lower portion of the shaft furnace at normal temperature, and the reducing gas that has flowed up in the cooling zone is used for reduction of the iron oxide.

A system for reducing ore includes a hydrogen supply unit configured to supply hydrogen, a furnace configured to reduce the ore using the supplied hydrogen, and a hydrogen recovery unit configured to recover hydrogen from an exhaust gas that is exhausted from the furnace.

A method of operating a metallurgic plant for producing iron products includes the following steps, wherein the metallurgic plant includes a direct reduction plant and an ironmaking plant, the metallurgic plant: feeding an iron ore charge into the direct reduction plant to produce direct reduced iron products, operating the ironmaking plant to produce pig iron, wherein biochar is introduced into the ironmaking plant as reducing agent, and whereby the ironmaking plant generates offgas containing CO and CO2, and treating offgas from the ironmaking plant in a hydrogen enrichment unit to form a hydrogen-rich stream and a CO2-rich stream. The hydrogen-rich stream is fed directly or indirectly to the direct reduction plant. The CO2-rich stream is converted to be valorized in the direct reduction plant.

A corresponding metallurgic plant is also related.