A process for producing direct reduced iron with a hydrogen rich gas, utilizing a non-fired reducing gas heater such as an electric heater to heat the reducing gas to the temperatures sufficient for iron reduction, includes: providing a shaft furnace to reduce iron oxide with the hydrogen rich reducing gas; removing steam and particulates from the shaft furnace top gas with a scrubber; processing all or a portion of the scrubbed top gas in a gas separation unit such as a membrane and a PSA gas separation unit to create a hydrogen rich stream to be recycled back to the shaft furnace as the reducing agent, so that the hydrogen consumption can be reduced when non-fired reducing gas heater is applied.

The present disclosure provides a facility to produce direct reduced iron, which makes it possible to perform reforming and reduction and adjust the carbon amount in a product within a wide range without requiring an externally heating reformer and without causing the metal dusting problem in a circulating gas preheater and the problem of sintering each other or fusion between reduced iron, in a furnace. The facility to produce the direct reduced iron according to the present invention is equipped with a water content control device for controlling the water content in a gas discharged from a shaft-type reduction furnace, a first gas mixing device for mixing the gas from which a portion of water has been removed with an oxygen-containing gas and a hydrocarbon-containing gas to produce a mixed gas, and an auto-thermal reformer for reforming the mixed gas with its energy. The facility is also equipped with a cooling gas loop for circulating a cooling gas, wherein the cooling gas has a hydrocarbon concentration of 50% or more, and the cooling gas loop is equipped with a cooling gas after-cooler having a flow rate control function and capable of controlling the temperature of the cooling gas.

A plant complex may include a unit that produces CO.sub.2-containing gases, a gas conducting system for CO.sub.2-containing gases, a gas/liquid separation system, a reformer that is connected to the gas conducting system and where the CO.sub.2-containing gas reacts with H.sub.2 and/or hydrocarbons to give a CO— and H.sub.2-containing synthesis gas mixture. The reformer is connected to a reactor for producing higher alcohols in which the synthesis gas mixture reacts with H.sub.2 to give a gas/liquid mixture containing higher alcohols. For separating off the alcohols of the gas/liquid mixture, the gas/liquid separation system is connected to the reactor for producing higher alcohols.

A method for producing direct reduced iron is provided. The method includes circulating a first stream of spent reducing gas exiting a reactor in a reducing gas circuit through at least one carbon dioxide removal unit and a reducing gas heater and the reactor. The method also includes mixing the first stream with reducing gas containing heavier hydrocarbons than methane.

Provided is a method of operating a blast furnace, having generating a regenerative methane gas from a by-product gas discharged from the blast furnace, and blowing a blast gas and a reducing agent into the blast furnace from a tuyere of the blast furnace in which the blast gas is oxygen gas and the regenerative methane gas is used as at least part of the reducing agent.

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.

Herein discussed is a method of producing hydrogen comprising introducing a metal smelter effluent gas or a basic oxygen furnace (BOF) effluent gas or a mixture thereof into an electrochemical (EC) reactor, wherein the EC reactor comprises a mixed-conducting membrane. In an embodiment, the method comprises introducing steam into the EC reactor on one side of the membrane, wherein the effluent gas is on the opposite side of the membrane, wherein the effluent gas and the steam are separated by the membrane and do not come in contact with each other.

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.

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.

Provided is a solid carbon production facility including: a separation facility configured to separate a carbon dioxide gas contained in a produced gas produced by a blast furnace; a reaction facility configured to heat a fuel gas whose main component is a methane gas by using a heating facility and decompose the methane gas into solid carbon and a hydrogen gas; and a production facility configured to cause the carbon dioxide gas separated by the separation facility and the hydrogen gas decomposed by the reaction facility to react with each other to produce solid carbon and water.