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 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.

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 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 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 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.