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公开(公告)号：US20210095354A1
公开(公告)日：2021-04-01
申请号：US17029778
申请日：2020-09-23
摘要： 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.
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公开(公告)号：US20190382857A1
公开(公告)日：2019-12-19
申请号：US16007045
申请日：2018-06-13
IPC分类号： C21B13/02
摘要： 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.
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公开(公告)号：US20230034215A1
公开(公告)日：2023-02-02
申请号：US17962640
申请日：2022-10-10
摘要： 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.
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4.发明申请公开(公告)号：US20210301358A1
公开(公告)日：2021-09-30
申请号：US17209506
申请日：2021-03-23
摘要： A method for producing direct reduced iron having increased carbon content, comprises: providing a carbon monoxide-rich gas stream, and separating the carbon monoxide-rich gas stream into at least two separate carbon monoxide-rich gas streams; providing a hydrocarbon-rich gas stream and separating the hydrocarbon-rich gas stream into at least two separate hydrocarbon-rich gas streams; blending one of the carbon monoxide-rich gas streams with one of the hydrocarbon-rich gas streams to form a mixed carburizing gas stream; blending another carbon monoxide-rich gas stream of the at least two separate carbon monoxide-rich gas streams with another hydrocarbon-rich gas stream of the at least two separate hydrocarbon-rich gas streams to form a distinct mixed carburizing gas stream; delivering each of the mixed carburizing gas streams, which are of different composition, to a transition zone of a direct reduction furnace, and exposing partially or completely reduced iron oxide to the mixed carburizing gas streams to increase the carbon content of resulting direct reduced iron to greater than 4.5 wt. %.
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