Abstract: A method of heating direct reduced iron between a direct reduced iron source and processing equipment for the direct reduced iron, comprises providing a conduit heater assembly between the direct reduced iron source and the processing equipment, wherein the conduit heater assembly receives a flow of the direct reduced iron from the direct reduced iron source and heats the direct reduced iron as the direct reduced iron flows through the conduit heater assembly and to the processing equipment.

Abstract: 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.

Abstract: A direct reduction plant is disclosed. The direct reduction plant includes an oxygen injection system, a reformer, and a shaft furnace. The oxygen injection system includes an oxygen injection reactor and a main oxygen burner. The oxygen injection reactor is adapted to receive a gas mixture. The main oxygen burner is adapted to increase a temperature of the gas mixture by burning a mixture of fuel and oxygen fed to the main oxygen burner. The reformer is adapted to reform the gas mixture with the increased temperature. The shaft furnace is adapted to reduce iron ore using the reformed gas mixture.

Abstract: A direct reduction process comprises providing a shaft furnace of a direct reduction plant to reduce iron oxide with reducing gas; providing a direct reduced iron melting furnace; and coupling a discharge chute between a discharge exit of the direct reduced shaft furnace and an inlet of the direct reduced iron melting furnace; wherein direct reduced iron and the reducing gas from the shaft furnace flow through the discharge chute and the reducing gas controls the melting furnace atmosphere to reducing environment.

Abstract: A method and system for operating a seal gas compressor utilized in a direct reduction process including: monitoring a pH level of a water stream used in the seal gas compressor, wherein the pH level of the water stream is affected by a reformer flue gas stream that comes into contact with the water stream, wherein the monitoring step is carried out one or more of upstream of the seal gas compressor and downstream of the compressor; and adjusting the pH level of the water stream to maintain the pH level of the water stream within a predetermined range based on feedback from the monitoring step. The method includes maintaining the pH level of the water stream upstream of the seal gas compressor in a range between 7.5 and 10 and maintaining the pH level of the water stream downstream of the seal gas compressor in a range between 7.8 and 9.5.

Abstract: 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.

Abstract: A method and apparatus for producing direct reduced iron (DRI), including: generating a reducing gas in a coal gasifier using coal, oxygen, steam, and a first coke oven gas (COG) stream as inputs to the coal gasifier; and delivering the reducing gas to a shaft furnace and exposing iron ore agglomerates to the reducing gas to form metallic iron agglomerates. The method further includes delivering a second COG stream directly to the shaft furnace.

Abstract: An oxygen injection system for a direct reduction process, including: a common circumferential gas injection header adapted to be coupled to an oxygen source and an enrichment natural gas source and adapted to deliver oxygen from the oxygen source and enrichment natural gas from the enrichment natural gas source to a reducing gas stream flowing through a conduit axially disposed within the common circumferential gas injection header through a plurality of circumferentially disposed ports to form a bustle gas stream; wherein the common circumferential gas injection header includes a circumferential oxygen injection header adapted to deliver the oxygen from the oxygen source to the reducing gas stream through the plurality of circumferentially disposed ports and a circumferential enrichment natural gas injection header adapted to deliver the enrichment natural gas from the enrichment natural gas source to the reducing gas stream through the plurality of circumferentially disposed ports.

Abstract: A direct reduction system and process for reducing a metal oxide to a metal, including and utilizing: a process gas line configured to deliver a portion of a process gas to a reformer operable for reforming the process gas to form a reformed gas; a bustle gas line configured to deliver the reformed gas to a shaft furnace as a bustle gas, wherein the shaft furnace is operable for reducing the metal oxide to the metal; and a direct recycle line including a direct recycle cooler configured to selectively deliver a portion of the process gas to the bustle gas line while circumventing the reformer, thereby selectively cooling and lowering the moisture content of the bustle gas delivered to the shaft furnace. Optionally, the direct reduction system further includes a reheat line configured to deliver a portion of the bustle gas to the shaft furnace as reheat gas.

Abstract: A shaft furnace for producing metallic direct reduced iron (DRI) from iron-containing pellets or lumps and reducing gas disposed therein, including: a circumferential outer wall defining a top interior reducing zone, a middle interior transition zone, and a bottom interior cooling zone, wherein the iron-containing pellets or lumps travel downwards through the top interior reducing zone, the middle interior transition zone, and the bottom interior cooling zone as the iron-containing pellets or lumps encounter the upward-flowing reducing gas and one or more other gases; and a flow diverter disposed along a centerline of the circumferential outer wall including a convex-upwards upper tapering section disposed in the middle transition zone defined by the circumferential outer wall coupled to a convex-downwards lower tapering section disposed in the bottom cooling zone defined by the circumferential outer wall.

Abstract: 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. 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 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.

Abstract: A method for mitigating the buildup of direct reduced iron (DRI) clusters on the walls of a direct reduction (DR) furnace, including: injecting one or more of lime, dolomite, and another anti-sticking agent into a charge disposed within a reduction zone of the DR furnace by: (1) injecting the one or more of lime, dolomite, and another anti-sticking agent into a bustle gas stream upstream of or in a bustle of the DR furnace; (2) injecting the one or more of lime, dolomite, and another anti-sticking agent into the bustle gas stream through a pipe collocated with a bustle gas port through which the bustle gas stream is introduced into the DR furnace; and (3) injecting the one or more of lime, dolomite, and another anti-sticking agent directly into the reduction zone of the DR furnace separate from the bustle gas stream.

Abstract: Methods and systems for producing direct reduced iron having increased carbon content, comprising: providing a reformed gas stream from a reformer; delivering the reformed gas stream to a carbon monoxide recovery unit to form a carbon monoxide-rich gas stream and a hydrogen-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 of a transition zone and a cooling zone of the direct reduction furnace. Optionally, the method further comprises mixing the carbon monoxide-rich gas stream with a hydrocarbon-rich gas stream.

Abstract: A method for producing high carbon content metallic iron using coke oven gas, including: dividing a top gas stream from a direct reduction shaft furnace into a first top gas stream and a second top gas stream; mixing the first top gas stream with a coke oven gas stream from a coke oven gas source and processing at least a portion of a resulting combined coke oven gas stream in a carbon dioxide separation unit to form a synthesis gas-rich gas stream and a carbon-dioxide rich gas stream; delivering the synthesis gas-rich gas stream to the direct reduction shaft furnace as bustle gas; using the carbon-dioxide rich gas stream as fuel gas in one or more heating units; and delivering the second top gas stream to the direct reduction shaft furnace as bustle gas.

Abstract: Processes that generate syngas or reformed gas that have the desired H2/CO ratio, such that they can be used directly for producing higher value liquids, such as using a FT GTL process. The systems and methods of the present invention are simpler and more cost effective than conventional systems and methods. The systems and methods of the present invention generate the required CO2 in a reforming furnace by combusting natural gas with a mixture of O2 from an external source and CO2 that is recirculated from a reforming furnace. A second application of the natural gas combustion with external O2 mixed with recirculated CO2 in the reformer burners can be utilized in a DR process. The reformed gas or syngas containing H2 and CO is used to reduce iron oxide to metallic iron in a shaft furnace, for example.

Abstract: The present disclosure provides a Fischer-Tropsch tail gas recycling system, including: a Fischer-Tropsch reactor providing a source of tail gas; a first preheater for preheating the tail gas to between about 200 and 300 degrees C.; a hydrogenator for hydrogenating the tail gas; an expansion device for reducing the pressure of the tail gas to between about 2.5 and 5 bar; a second preheater for preheating a feed gas comprising the tail gas and steam to between about 500 and 600 degrees C.; and a catalytic reformer for reforming the feed gas in the presence of a catalyst, wherein the catalytic reformer operates at about 2 bar and about 1000 degrees C., for example. Optionally, CO2 and/or natural gas are also added to the tail gas and/or steam to form the feed gas.

Abstract: The present invention provides a method for reducing iron oxide to metallic iron using coke oven gas, including: dividing coke oven gas from a coke oven gas source into a plurality of coke oven gas streams; providing a first coke oven gas stream to a hydrogen enrichment unit to form a hydrogen-rich product stream that is delivered to a reduction shaft furnace as part of a reducing gas stream; and providing a tail gas stream from the hydrogen enrichment unit to a reforming reactor to form a reformed gas stream that is delivered to a reduction shaft furnace as part of the reducing gas stream. Optionally, a spent top gas stream from the reduction shaft furnace is cleansed of CO2 and recycled back to the reducing gas stream.

Abstract: A method and apparatus for producing direct reduced iron (DRI), including: generating a reducing gas in a coal gasifier using coal, oxygen, steam, and a first coke oven gas (COG) stream as inputs to the coal gasifier; and delivering the reducing gas to a shaft furnace and exposing iron ore agglomerates to the reducing gas to form metallic iron agglomerates. The method further includes delivering a second COG stream directly to the shaft furnace.

Abstract: A shaft furnace for producing metallic direct reduced iron (DRI) from iron-containing pellets or lumps and reducing gas disposed therein, including: a circumferential outer wall defining a top interior reducing zone, a middle interior transition zone, and a bottom interior cooling zone, wherein the iron-containing pellets or lumps travel downwards through the top interior reducing zone, the middle interior transition zone, and the bottom interior cooling zone as the iron-containing pellets or lumps encounter the upward-flowing reducing gas and one or more other gases; and a flow diverter disposed along a centerline of the circumferential outer wall including a convex-upwards upper tapering section disposed in the middle transition zone defined by the circumferential outer wall coupled to a convex-downwards lower tapering section disposed in the bottom cooling zone defined by the circumferential outer wall.

Abstract: A process for producing reducing gas for use in the production of direct reduced iron (DRI) and fuel gas for use in a steel mill, including: compressing a coke oven gas (COG) stream in a compressor; passing the compressed coke oven gas stream through an activated charcoal bed to remove tars from the compressed coke oven gas stream; separating a hydrogen-rich gas stream from the compressed cleaned coke oven gas stream using a pressure swing absorption unit; providing the hydrogen-rich gas stream to a direct reduction shaft furnace as reducing gas; and providing a remaining gas stream from the pressure swing absorption unit to a steel mill as fuel gas. Both once-through and recycle options are presented. Optionally, basic oxygen furnace gas (BOFG) is added to the reducing gas.