Improved processes and systems are disclosed for producing renewable hydrogen suitable for reducing metal ores, as well as for producing activated carbon. Some variations provide a process comprising: pyrolyzing biomass to generate a biogenic reagent comprising carbon and a pyrolysis off-gas; converting the pyrolysis off-gas to additional reducing gas and/or heat; reacting at least some of the biogenic reagent with a reactant to generate a reducing gas; and chemically reducing a metal oxide in the presence of the reducing gas. Some variations provide a process for producing renewable hydrogen by biomass pyrolysis to generate a biogenic reagent, conversion of the biogenic reagent to a reducing gas, and separation and recovery of hydrogen from the reducing gas. A reducing-gas composition for reducing a metal oxide is provided, comprising renewable hydrogen according to a hydrogen-isotope analysis. Reacted biogenic reagent may also be recovered as an activated carbon product. Many variations are disclosed.

In a method for oxygen-blowing refining of molten iron, an oxygen-containing gas as a main supply gas is supplied from an inlet side of a blowing nozzle for the oxygen-containing gas passing through an outer shell of the top-blowing lance and blown from the blowing nozzle while a control gas is jetted toward inside of the blowing nozzle for at least part of a period of the oxygen-blowing refining from a spout arranged in a side face of the nozzle at a site where the cross-sectional area of the nozzle minimum takes the minimum in the axial direction of the nozzle or a neighborhood thereof so that at least part of the spout exists in each space formed by dividing into two portions by an arbitrary plane passing through a central axis of the nozzle.

In a method for oxygen-blowing refining of molten iron, an oxygen-containing gas as a main supply gas is supplied from an inlet side of a blowing nozzle for the oxygen-containing gas passing through an outer shell of the top-blowing lance and blown from the blowing nozzle while a control gas is jetted toward inside of the blowing nozzle for at least part of a period of the oxygen-blowing refining from a spout arranged in a side face of the nozzle at a site where the cross-sectional area of the nozzle minimum takes the minimum in the axial direction of the nozzle or a neighborhood thereof so that at least part of the spout exists in each space formed by dividing into two portions by an arbitrary plane passing through a central axis of the nozzle.

An optically based combustion off-gas stream velocity sensor assembly is provided for detecting in real-time off-gas flow velocity and/or volume as it moves through a flue duct. The sensor assembly includes two paired coherent light emitters and optic sensors, positioned in a spaced orientation in the flow path direction. The light emitter/optic sensor pairs operate to emit and detect across the off-gas stream coherent light beam energy having a wavelength component corresponding to an absorption profile of an off-gas species component. The detection of non-absorbed portions of the emitted beam is used to identify and detect the movement of a flow species signature at different locations along the flue duct.

When the decarburization refining of molten iron is performed by top-blowing oxygen gas from the top blowing lance, the oscillation of molten iron, a bubble burst, and spitting due to the bubble burst are suppressed. A refining method for a converter includes decarburizing molten iron in the converter with a top blowing lance having Laval nozzles disposed at the lower end thereof by blowing oxygen gas on the surface of the molten iron in the converter through the Laval nozzles, in which one or both of an oxygen feeding rate from the top blowing lance and lance height LH are adjusted in such a manner that an oxygen accumulation index S(F) is 40 or less.

When the decarburization refining of molten iron is performed by top-blowing oxygen gas from the top blowing lance, the oscillation of molten iron, a bubble burst, and spitting due to the bubble burst are suppressed. A refining method for a converter includes decarburizing molten iron in the converter with a top blowing lance having Laval nozzles disposed at the lower end thereof by blowing oxygen gas on the surface of the molten iron in the converter through the Laval nozzles, in which one or both of an oxygen feeding rate from the top blowing lance and lance height LH are adjusted in such a manner that an oxygen accumulation index S(F) is 40 or less.

Methods for controlling the position of a lance supplying oxygen to a furnace containing a bath of molten metal. The methods include the steps of continuously detecting actual conditions associated with the furnace, continuously comparing the actual conditions to target parameters corresponding to the actual conditions, and continuously adjusting the position of the lance with respect to the furnace based on the comparison of the actual conditions to the target parameters.

Methods for controlling the position of a lance supplying oxygen to a furnace containing a bath of molten metal. The methods include the steps of continuously detecting actual conditions associated with the furnace, continuously comparing the actual conditions to target parameters corresponding to the actual conditions, and continuously adjusting the position of the lance with respect to the furnace based on the comparison of the actual conditions to the target parameters.

An improved apparatus for producing steel, including a lower furnace, an annular, water-cooled, fireproof lined cylindrical upper furnace, on which an upwardly closing conically tapering hat having openings can be placed. The smelting assembly is configured for the operational mode without melt flow and the operational mode with melt flow. To this end, at least one opening is provided in the conical furnace cover, through which opening at least one top lance can be introduced into the upper furnace. A plurality of sidewall injectors radially rotate around the cylindrical upper furnace in such a way that in a working position, the top lance and the sidewall injectors are directed onto a smelt level of a molten mass located in the lower furnace for refining.

A molten metal component estimation device including: an input device configured to receive measurement information about a refining facility including measurement results regarding an optical characteristic; a model database that stores model expressions and model parameters, regarding a blowing process reaction, including a model expression and model parameters representing a relation between the oxygen efficiency in decarburization and a carbon concentration in a molten metal in the refining facility; and a processor configured to: estimate component concentrations of the molten metal including the carbon concentration in the molten metal by using the measurement information, the model expressions and the model parameters; estimate the carbon concentration in the molten metal based on the measurement results; and determine the model expression and the model parameters to be used when estimating the component concentrations of the molten metal, based on the estimation result of the carbon concentration in the molten metal.