Midrex Technologies, Inc.

Midrex International, B.v., Rotterdam, Zurich Branch

Gary Edward Metius

James M McClelland, Jr

David C Meissner

Stephen Craig Montague

Gregory Darel Hughes

Russell Kakaley

Brian William Voelker

Robert B Cheeley

Gilbert Y Whitten

Russell Eugene Bailey

Matthew C Stubbing

James M Mcclelland

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.

Systems and methods for generating carbon dioxide for use as a reforming oxidant in making syngas or reformed gas

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.

Systems and methods for the use of Fischer-Tropsch tail gas in a gas to liquid process

Methods and systems for producing direct reduced iron (DRI), comprising: generating a syngas stream in a carbon dioxide (CO2) and steam reformer; and providing the syngas stream to a direct reduction (DR) shaft furnace as a reducing gas stream. The methods and systems also comprise combining the syngas stream with a recycled off-gas stream from the DR shaft furnace to form the reducing gas stream. The methods and systems further comprise removing carbon dioxide (CO2) from the recycled off-gas stream from the DR shaft furnace prior to combining it with the syngas stream to form the reducing gas stream. The methods and systems still further comprise feeding CO2 removed from the recycled off-gas stream from the DR shaft furnace to the CO2 and steam reformer. The methods and systems still further comprise feeding recycled off-gas from the recycled off-gas stream from the DR shaft furnace to the CO2 and steam reformer.

Methods and systems for producing direct reduced iron incorporating a carbon dioxide and steam reformer fed by recovered carbon dioxide

In various exemplary embodiments, the present invention provides systems and methods that can convert clean or raw natural gas, clean or dirty coke oven gas, or the like to reducing gas/syngas suitable for direct reduction with minimal processing or cleaning. Hydrocarbons and the like are converted to Hand CO. S does not affect the conversion to reducing gas/syngas, but is removed or otherwise cleaned up by the iron bed in the direct reduction shaft furnace. Top gas may be continuously recycled or a once-through approach may be employed.

System and method for reducing iron oxide to metallic iron using natural gas

Novel systems and methods are described for reducing iron oxide to metallic iron in an integrated steel mill or the like that has a coke oven and/or an oxygen steelmaking furnace. More specifically, the present invention relates to novel systems and methods for reducing iron oxide to metallic iron using coke oven gas (COG) or COG and basic oxygen furnace gas (BOFG).

System and method for reducing iron oxide to metallic iron using coke oven gas and oxygen steelmaking furnace gas

A method and apparatus for sequestering carbon dioxide from a waste gas and reusing it as a recycled gas without emissions concerns, including: given a gas source divided into a process gas and a waste gas: mixing the process gas with a hydrocarbon and feeding a resulting feed gas into a reformer for reforming the feed gas and forming a reducing gas; and feeding at least a portion of the waste gas into a carbon dioxide scrubber for removing at least some carbon dioxide from the waste gas and forming a carbon dioxide lean gas that is mixed with the reducing gas. Optionally, the method also includes feeding at least a portion of the waste gas into the carbon dioxide scrubber for removing at least some carbon dioxide from the waste gas and forming a fuel gas after the addition of a hydrocarbon that is fed into the reformer. Optionally, the gas source and the reducing gas are associated with a direct reduction process for converting iron oxide to metallic iron in a reduction furnace that utilizes the reducing gas, optionally after some modification, and produces the gas source.

Method and apparatus for sequestering carbon dioxide from a spent gas

Methods and systems for the production of direct reduced iron, including: removing a top gas from a direct reduction furnace; carbon monoxide shifting the top gas using a carbon monoxide shift reactor to form a carbon monoxide shifted top gas having a reduced carbon monoxide content; adding one of a coal gas, a synthesis gas, and an export gas to at least a portion of the carbon monoxide shifted top gas to form a combined gas; removing carbon dioxide from the combined gas using a carbon dioxide removal unit to form a carbon dioxide lean combined gas; and providing the carbon dioxide lean combined gas to the direct reduction furnace as a reducing gas for producing direct reduced iron after heating to reduction temperature. Optionally, the method includes removing carbon dioxide from the top gas using a carbon dioxide removal unit prior to carbon monoxide shifting the top gas.

Method and system for the production of direct reduced iron using a synthesis gas with a high carbon monoxide content

A process for reducing iron oxide to metallic iron using coke oven gas (COG), including: a direct reduction shaft furnace for providing off gas; a COG source for injecting COG into a reducing gas stream including at least a portion of the off gas; and the direct reduction shaft furnace reducing iron oxide to metallic iron using the reducing gas stream and injected COG. The COG has a temperature of about 1,200 degrees C. or greater upon injection. The COG has a CHcontent of between about 2% and about 13%. Preferably, the COG is reformed COG. Optionally, the COG is fresh hot COG. The COG source includes a partial oxidation system. Optionally, the COG source includes a hot oxygen burner.

A process for the direct reduction of iron ore when the external source of reductants is one or both of coke oven gas (COG) and basic oxygen furnace gas (BOFG). Carbon dioxide (CO) is removed from a mixture of shaft furnace off gas, obtained from a conventional direct reduction shaft furnace, and BOFG. This COlean gas is mixed with clean COG, humidified, and heated in an indirect heater. Oxygen (O) is injected into the heated reducing gas. This hot reducing gas flows to the direct reduction shaft furnace for use. The spent hot reducing gas exits the direct reduction shaft furnace as shaft furnace off gas, produces steam in a waste heat boiler, is cleaned in a cooler scrubber, and is compressed and recycled to join fresh BOFG. A portion of the shaft furnace off gas is sent to the heater burners. The BOFG and COG are also employed for a variety of other purposes in the process.

The present invention relates generally to a method and system for the supply of a continuous stream of hot direct reduced iron (HDRI) from a direct reduction (DR) shaft furnace or direct reduced iron (DRI) reheating furnace to a point outside of the DR shaft furnace or DRI reheating furnace where the HDRI stream is split into at least two HDRI streams. The first HDRI stream is sent continuously to a hot briquetting plant by gravity in a closed duct system. The second HDRI stream is sent continuously to an adjacent melting furnace also by gravity in a closed duct system, with a surge bin and feeders, or by a combination of gravity in a closed duct system, also with a surge bin and feeders, and a generally horizontal charge conveyor. Optionally, a third HDRI stream is employed to continuously feed multiple hot transport vessels.

Method and system for the supply of hot direct reduced iron for multiple uses

A method and apparatus for increasing hydrocarbons to a direct reduction shaft furnace while controlling the temperature uniformity of the center portion of the iron burden wherein the hydrocarbon gases used in direct reduction may be preheated, which increases the temperature of the hydrocarbon gases, and therefore increases the resultant temperature of the upflowing gases as it rises from the lower section of the furnace into the center of the burden. Alternatively, a portion of the upflowing gas may be removed before it enters the reduction zone of the furnace. The removed upflowing gas, known as hot bleed gas, may be ducted to the top gas scrubber of the furnace or may be mixed with the main reducing gas stream of the furnace for reintroduction to the furnace. Alternatively, hot reducing gas may be directly injected into the center portion of the burden, offsetting the cooling effect of the upflowing gas. The center injected hot reducing gas may be split off from the main reducing gas stream or may be generated by a partial oxidation reactor.

Method and apparatus for controlling temperature uniformity of the burden in a direct reduction shaft furnace

An improved method and apparatus for increasing the productivity of a direct reduction process in which iron oxide is reduced to metallized iron by contact with hot reducing gas; comprising the steps of: a) providing a first hot reducing gas consisting essentially of CO and H ; b) providing additional reducing gas by reaction of a gaseous or liquid hydrocarbon fuel with oxygen; c) mixing the first hot reducing gas with the additional reducing gas to form a reducing gas mixture; d) enriching the reducing gas mixture by the addition of a gaseous or liquid hydrocarbon; e) injecting oxygen or oxygen-enriched air into the enriched mixture; and f) introducing the enriched mixture into an associated direct reduction furnace as reducing gas.

Method for increasing productivity of direct reduction process

A method and apparatus for discharging cold product or a combination of cold and hot products from a continuous supply of hot direct reduced iron (&ldquo;DRI&rdquo;) comprising a product cooler connected to a shaft furnace, with downward movement of the hot DRI and upward concurrent flow of cooling gas through the product cooler. The method and apparatus provides for diverting of hot DRI from an upper portion of the cooler for gravitational transfer to an adjacent storage unit located at a lower elevation than the furnace. The product cooler is situated at a lower height in relation to the furnace, for gravity transfer of a continuous supply of hot DRI through an entry point into the cooler. Cooler provides for cooling gas injection into the lower portion of the cooler, with gas flow upward and counter-current to the hot DRI that descends through the cooler. Recovered cooling gas is scrubbed, cooled, and recycled back for injection into the bottom portion of the cooler. The cooled DRI is removed from the bottom portion of the cooler thereby establishing a gravitational movement of DRI through the cooler. Simultaneous to cooling of the DRI material, separate transfer portions of hot DRI material can be diverted at the top of the cooler with gravitational transfer to one or more adjacent storage units for processing.

Growing community of inventors

Charlotte, NC, United States of America

Gary Edward Metius