C21B2100/26

DIRECT REDUCTION PROCESS UTILIZING HYDROGEN

A direct reduction method/system, including: adding variable amounts of natural gas, hydrogen, and a carbon-free oxidizing gas to a feed gas stream upstream of a reformer; reforming the feed gas stream in the reformer to form a reformed gas stream, and delivering the reformed gas stream to a shaft furnace, where the reformed gas stream is used to reduce a metallic ore material to a direct reduced metallic material. The feed gas stream includes a top gas stream recycled from the shaft furnace. Optionally, the carbon-free oxidizing gas includes steam and the method further includes controlling a steam flow rate of the steam to maintain a maximum k-factor value of the feed gas stream of 0.74 or lower. Optionally, the variable amount of hydrogen is selected to replace 20-90% of the natural gas by fuel value. The variable amount of hydrogen is selected based upon an available supply of hydrogen.

Method for supplying hydrogen-containing reducing gas to shaft part of blast furnace

The present invention provides a novel method for supplying a reducing gas to the shaft part of a blast furnace with which a large amount of reducing gas containing hydrogen at a high concentration can be supplied to a deeper position in the blast furnace (location of the blast furnace closer to the center axis in the radial direction) and with which it is possible to reduce the total generated amount of CO.sub.2 of the CO.sub.2 amount that is reduced by conducting hydrogen smelting in the blast furnace and the CO.sub.2 amount that is generated during production of the reducing gas supplied to the blast furnace. The method for supplying a reducing gas to the shaft part of a blast furnace according to the present invention is characterized by reforming coke oven gas by increasing the temperature thereof to 1200 to 1800 C. in a reactor in which an oxygen-containing gas is supplied to preheated coke oven gas to generate reformed gas in which hydrogen gas is enriched; mixing the reformed gas with CO-containing gas in the reactor so that the hydrogen concentration of the reducing gas is adjusted to 15-35 vol % (wet); and supplying the resultant reducing gas to the shaft part of the blast furnace under a condition of a ratio of a flow rate of reducing gas blown into shaft part/flow rate of reducing gas blown into tuyere >0.42.

DIRECT REDUCTION PROCESS UTILIZING HYDROGEN

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.

METHOD FOR PRODUCING PIG IRON IN A SHAFT FURNACE
20240018615 · 2024-01-18 · ·

A method of producing pig iron in a shaft furnace is provided. The shaft furnace is charged in an upper region with raw materials which fall within the shaft furnace under the influence of gravity. A portion of the raw materials is melted and/or partly reduced under the action of the atmosphere that exists within the shaft furnace. A hot gas stream which is introduced in a lower region of the shaft furnace flows through and influences the atmosphere that exists within the shaft furnace in terms of chemical composition and temperature. A cold gas stream is fed to a heat exchanger in which the cold gas stream is heated to a temperature higher than 700 C. to give a hot gas stream. The cold gas stream comprises a CO.sub.2 component of at least 5% by volume. The cold gas stream may contain, air and/or pure oxygen as residual component.

PROCESS FOR THE PRODUCTION OF CARBURIZED SPONGE IRON
20240035103 · 2024-02-01 ·

A process for the production of carburized sponge iron, including charging iron ore into a direct reduction shaft, and/or discharging carburized sponge iron from the direct reduction shaft, whereby a seal gas is introduced into the direct reduction shaft; removing a top gas from the direct reduction shaft; recycling a proportion of the top gas and mixing with a make-up gas to form a reducing gas; and introducing the reducing gas into the direct reduction shaft in countercurrent flow to the iron ore in order to reduce the iron ore and produce carburized sponge iron. The seal gas consists essentially of carbon dioxide, and the make-up gas comprises greater than 80 vol % hydrogen gas. Also provided is a system for the production of carburized sponge iron, as well as a carburized sponge iron produced by the aforementioned process.

BLEED-OFF GAS RECOVERY IN A DIRECT REDUCTION PROCESS
20240084410 · 2024-03-14 ·

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.

SMART HYDROGEN PRODUCTION FOR DRI MAKING

The invention relates to the production of direct reduced iron, DRI, where a hydrogen direct reduction is synergistically operated in the context of an industrial plant. The hydrogen reduction operates with reducing gas comprising at least 85 vol. % hydrogen, and receives a make-up hydrogen stream. At least part of the make-up hydrogen stream is produced on site. by at least one of (i) electrolysis means configured to produce hydrogen from steam recovered from one or more components of the industrial plant and/or from steam generated using waste heat and/or hot gases emitted by the one or more components; and (ii) gas shift reactor means configured to convert CO-bearing gas emitted by at least one component of the industrial plant into hydrogen and to remove CO.sub.2.

METAL OXIDE MATERIAL REDUCTION MEANS

A method of reduction of a metal oxide material and a metal material production configuration adapted for manufacture of reduced metal material, a metal oxide material production unit produces a metal oxide material holding thermal energy, a direct reduction facility is configured for introduction of a reducing agent adapted to react with the metal oxide material. The method includes the steps of; charging the metal oxide material, holding thermal energy; introducing the reducing agent; reducing the metal oxide material to reduced metal material by utilizing the thermal energy of the metal oxide material to heat or further heat the introduced reducing agent for achieving a chemical reaction; and discharging the reduced metal material from the direct reduction facility.

A direct reduction facility and a data program configured to execute an automatic or semi-automatic manufacture of reduced metal material ready to be transported to a metal production site.

Direct reduction process utilizing hydrogen

A direct reduction method/system, including: adding variable amounts of natural gas, hydrogen, and a carbon-free oxidizing gas to a feed gas stream upstream of a reformer; reforming the feed gas stream in the reformer to form a reformed gas stream, and delivering the reformed gas stream to a shaft furnace, where the reformed gas stream is used to reduce a metallic ore material to a direct reduced metallic material. The feed gas stream includes a top gas stream recycled from the shaft furnace. Optionally, the carbon-free oxidizing gas includes steam and the method further includes controlling a steam flow rate of the steam to maintain a maximum k-factor value of the feed gas stream of 0.74 or lower. Optionally, the variable amount of hydrogen is selected to replace 20-90% of the natural gas by fuel value. The variable amount of hydrogen is selected based upon an available supply of hydrogen.

System and method for reducing ore using hydrogen as a reducing agent

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.