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EP4379069A1 - Réduction de lit fluidisé à base d'hydrogène - Google Patents

Réduction de lit fluidisé à base d'hydrogène Download PDF

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Publication number
EP4379069A1
EP4379069A1 EP23163719.0A EP23163719A EP4379069A1 EP 4379069 A1 EP4379069 A1 EP 4379069A1 EP 23163719 A EP23163719 A EP 23163719A EP 4379069 A1 EP4379069 A1 EP 4379069A1
Authority
EP
European Patent Office
Prior art keywords
fluidized bed
gas
reducing gas
heating
reduction
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP23163719.0A
Other languages
German (de)
English (en)
Inventor
Franz Hauzenberger
Robert Millner
Norbert Rein
Johann Wurm
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Primetals Technologies Austria GmbH
Original Assignee
Primetals Technologies Austria GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Primetals Technologies Austria GmbH filed Critical Primetals Technologies Austria GmbH
Publication of EP4379069A1 publication Critical patent/EP4379069A1/fr
Pending legal-status Critical Current

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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/0073—Selection or treatment of the reducing gases
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/0033—In fluidised bed furnaces or apparatus containing a dispersion of the material
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/14—Multi-stage processes processes carried out in different vessels or furnaces
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B2100/00—Handling of exhaust gases produced during the manufacture of iron or steel
    • C21B2100/20—Increasing the gas reduction potential of recycled exhaust gases
    • C21B2100/26—Increasing the gas reduction potential of recycled exhaust gases by adding additional fuel in recirculation pipes
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B2100/00—Handling of exhaust gases produced during the manufacture of iron or steel
    • C21B2100/60—Process control or energy utilisation in the manufacture of iron or steel
    • C21B2100/64—Controlling the physical properties of the gas, e.g. pressure or temperature
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B2100/00—Handling of exhaust gases produced during the manufacture of iron or steel
    • C21B2100/60—Process control or energy utilisation in the manufacture of iron or steel
    • C21B2100/66—Heat exchange

Definitions

  • the application relates to a method for producing a metallized product from metal oxide-containing material, comprising fluidized bed reduction of the metal oxide-containing material, in which at least a first reducing gas comprising hydrogen and nitrogen is used. It also relates to a device for producing a metallized product from metal oxide-containing material using a first reducing gas with a hydrogen content of at least 70 vol% and a nitrogen content of 5 vol% to 30 vol%.
  • Reduction of iron oxide-containing material with hydrogen H2 is endothermic.
  • Energy can be supplied via the reducing gas and can be controlled or regulated, for example, via the amount and temperature of the reducing gas supplied. If reducing components of the reducing gas - such as hydrogen H2 - are used as heat carriers in order to introduce the energy required to maintain a desired temperature for endothermic reaction processes into the reduction unit, these components must be provided in quantities that are significantly overstoichiometric with respect to the reduction reactions.
  • Reducing components of the reducing gas provided overstoichiometrically are not consumed during the reduction and can be recirculated after leaving the reduction unit.
  • Provision of reducing components, especially of hydrogen H2 is usually associated with expenditure in terms of costs, energy, and necessary equipment. In order to keep this expenditure to a minimum, efforts are made to avoid providing superstoichiometric amounts of reducing components wherever possible.
  • the presence of carbon in direct reduced iron (DRI) is desirable because its presence contributes to lowering the melting temperature when melting the DRI, it can have a reducing effect and it can serve as an energy supplier.
  • Carbon is available in reduction processes using carbon- and/or hydrocarbon-containing reducing agents in the reducing gas.
  • the reducing agent hydrogen H2 does not provide any carbon, which can be contained in the resulting metallized reduction product. This brings with it disadvantages with regard to the processability of the iron directly reduced with this reducing agent.
  • the aim is to present methods and devices that make it possible to reduce or avoid at least some of the disadvantages mentioned above.
  • the material containing metal oxide is preferably iron oxide-containing material.
  • the metal oxide-containing material is reduced by the first reducing gas - and optionally one or more further reducing gases, such as a second reducing gas.
  • a fluidized bed reduction the metal oxide-containing material is fluidized by a stream of reducing gas, i.e. kept in a fluidized bed. It is known that good heat exchange takes place between the reducing gas and the metal oxide-containing material, and a large surface is available for reactions to take place between the reducing gas and the metal oxide-containing material.
  • the metallized product has a degree of metallization which is higher than the degree of metallization of the metal oxide-containing material.
  • the metallized product can be the reduction product of the fluidized bed reduction - if the process only comprises fluidized bed reduction - or it can be obtained by a further treatment of the reduction product of the fluidized bed reduction which may be additionally carried out in the process for producing a metallized product.
  • the first reducing gas comprises or contains at least hydrogen H2 and nitrogen N2; if these are the only components of the first reducing gas, it consists of hydrogen H2 and nitrogen N2.
  • the hydrogen H2 content is at least 70 vol%.
  • Hydrogen H2 serves as the reducing component of the first reducing gas.
  • Hydrogen H2 can be the only reducing component of the first reducing gas, or other reducing components can be present in the first reducing gas in addition to hydrogen H2; for example, supplied from reforming of natural gas such as steam reforming or CO2 reforming.
  • the nitrogen N2 content is at least 5 vol% and up to 30 vol%, preferably up to 20 vol%.
  • One function of nitrogen is to transport heat into the fluidized bed; heat transported by it into the fluidized bed does not have to be introduced into the fluidized bed by reducing components of the first reducing gas. The more nitrogen there is, the fewer reducing components of the first reducing gas have to be provided in excess of stoichiometric amounts for heat transport. With a nitrogen content of more than 30 vol%, however, the reducing power of the first reducing gas would be too limited by the high proportion of nitrogen, which is inert with regard to the reduction of the metal oxide-containing material.
  • the nitrogen content in the first reducing gas should be at least 5 vol% so that the effect as a heat carrier or the reduction of the need to provide reducing components of the first reducing gas in superstoichiometric quantities is sufficiently pronounced.
  • the first reducing gas may also be present in the first reducing gas, such as water H2O, carbon monoxide CO, carbon dioxide CO2, and higher hydrocarbons.
  • the quality of the reduction gas can be changed by the nitrogen N2 content in the first reduction gas.
  • the quality of the reduction gas and the temperature in different fluidized beds and thus the reduction rate can be changed by the nitrogen content, and the location of the reduction in the reduction unit comprising several fluidized bed reactors containing the fluidized beds can be changed.
  • the reducing gas quality is expressed, for example, as GOD (Gas Oxidation Degree) which is defined as follows: (H2O+CO2)/(H2O+CO2+H2+CO), i.e. as the ratio of the corresponding sums of concentrations of the individual components in vol% for the components water H2O, carbon dioxide CO2, hydrogen H2, carbon monoxide CO.
  • GOD Gas Oxidation Degree
  • the sum of the concentrations of carbon monoxide CO and hydrogen H2 in vol% is an indication of the reducing gas quality of the reducing gas, since these components are required for the reduction.
  • the reduction rate describes the removal of oxygen per unit of time, for example in kilograms (kg oxygen per second s). If the mass flow rate of iron is variable, the specific reduction rate can also be used as kg oxygen per kg iron and per s (kg O / (kg Fe * s)).
  • the increasing proportion of nitrogen N2 in the first reducing gas also enables simpler nozzle design when using gas distribution plates with nozzles to create a fluidized bed due to its higher molecular weight, higher density and higher viscosity.
  • the fluidization properties of the fluidized bed can also be changed - for example, smaller bubble size and higher expansion of the fluidized bed with an increasing proportion of nitrogen N2 compared to hydrogen due to its higher density and viscosity compared to hydrogen.
  • the first reducing gas must be under pressure and must therefore be compressed; an increasing proportion of nitrogen N2 in the first reducing gas compared to hydrogen H2 can have advantages during compression due to its higher molecular weight, for example when using radial compressors for compression.
  • the metallized product of the process according to the invention for example the reduction product of the fluidized bed reduction - has a metallization of at least 80%, preferably at least 85%. It can serve as a basis for the production of steel in subsequent processing steps.
  • a mixture of gases containing components of the first reducing gas is subjected to heating.
  • the heating can take place in several steps, whereby the type of heating used in the various steps can differ from one another.
  • the heated mixture can be fed to the fluidized bed of the fluidized bed reduction, whereby further components can optionally be added in order to set the desired composition for the first reducing gas.
  • a gas mixture entering the fluidized bed has a certain temperature, a certain pressure and a certain composition; it has a reducing effect in the fluidized bed and is the first reducing gas. Before this temperature, pressure and composition are present, the gas mixture is referred to in this application as the reducing gas precursor of the first reducing gas.
  • heating of a reducing gas precursor of the first reducing gas takes place before entering the fluidized bed, this is preferably done at least partially by means of electrical heating.
  • Electrical heating can be, for example, resistance heating or heating by means of a plasma produced using electrical energy. Compared to heating using a reducing gas furnace with a burner, electrical heating has the advantage that no exhaust gases are produced and less energy is lost. In a reducing gas furnace with a burner, indirect heat exchange takes place between the flue gas from the combustion carried out with the burner and the reducing gas precursor.
  • heating with an indirect heat exchanger - preferably from waste heat from the top gas of the fluidized bed reduction -
  • heating using a reducing gas furnace with burner heating by partial oxidation with oxygen or combinations of two or more of these.
  • One burner or several burners can be used in a reducing gas furnace.
  • Gas with calorific value generated during fluidized bed reduction can be used for energy purposes, which improves the energy efficiency of the process.
  • Heating of a reducing gas precursor of the first reducing gas can also be carried out without electrical heating by another type of heating; for example, heating with an indirect heat exchanger from waste heat of the top gas of the fluidized bed reduction, heating by means of a reducing gas furnace with burner, heating by partial oxidation with oxygen or combinations of two or more thereof.
  • a gas stream of reducing gas is introduced into the fluidized bed(s) and flows through the fluidized bed(s), where it is partially consumed as a result of the performance of reduction work.
  • Used reducing gas is discharged; it is also called top gas.
  • Reducing gas used during fluidized bed reduction - i.e. top gas - is used up in the sense of a reduction in the reduction potential.
  • Used reducing gas has a lower reduction potential than fresh reducing gas because at least some of the originally present reducing components have been used up, but it can still have a reduction potential if it still contains reducing components.
  • the top gas still contains reducing components - for example when using the first reducing gas, hydrogen H2 - so recirculation of top gas or use of top gas to prepare the first reducing gas is sensible.
  • top gas also contains nitrogen N2.
  • N2 nitrogen
  • the top gas also contains reducing components, it also has a calorific value.
  • top gas discharged from the recirculation circuit As fuel.
  • the calorific value of the discharged top gas can be used energetically in the process, which improves the energy efficiency of the process. Burners can also be operated with other fuels, or with mixtures of other fuels and discharged top gas.
  • the electrical heating can, for example, take place before heating by means of a reducing gas furnace with burner and/or afterwards. It is preferable to carry out electrical heating after heating by means of a reducing gas furnace with burner. This allows the use of less temperature-resistant materials for the reducing gas furnace and leads to less energy loss in the exhaust gas of the reducing gas furnace.
  • a reducing gas precursor of the first reducing gas is heated at least partially by means of heat exchange with top gas.
  • the heat content of the discharged top gas can be used energetically in the process, which improves the energy efficiency of the process.
  • other types of heating can also be used, for example the types of electrical heating mentioned above and heating by means of a reducing gas furnace with burner, heating by partial oxidation.
  • heating can begin with an indirect heat exchanger from waste heat of the top gas of the fluidized bed reduction, followed by electrical heating, followed by heating using a reducing gas furnace with burner, followed by direct heating of the fuel gas using partial oxidation.
  • electrical heating it may be useful to swap the order of electrical heating and reducing gas furnace.
  • heating of a reducing gas precursor of the first reducing gas is carried out by indirect heat exchange with top gas before electrical heating or heating by means of a reducing gas furnace with burner is carried out.
  • the first reducing gas comprises at least one hydrocarbon-containing gas.
  • hydrocarbon-containing gas - for example methane, natural gas, higher hydrocarbons - is then mixed with hydrogen H2 and nitrogen N2.
  • One hydrocarbon-containing gas or several hydrocarbon-containing gases can be used.
  • the proportion of hydrocarbon-containing gas in the first reducing gas can be up to 25 vol%, preferably up to 15 vol%.
  • the addition of hydrocarbon-containing gas can be carried out, for example, before heating a reducing gas precursor of the first reducing gas. It can also be carried out after heating a reducing gas precursor of the first reducing gas.
  • the hydrocarbon-containing gas enables the introduction of carbon into the reduction product - metallized by the fluidized bed reduction.
  • it can be used to transport heat into the fluidized bed; thus, it can help to reduce the amount of nitrogen required for a certain amount of heat to be introduced by a gas other than hydrogen. It therefore makes it easier to set a certain nitrogen content and helps to counteract an enrichment of nitrogen during recirculation.
  • the fluidized bed reduction of the process according to the invention is carried out in at least one fluidized bed and produces a reduction product that is metallized.
  • hydrocarbon-containing gas is added to at least one fluidized bed of the fluidized bed reduction, preferably to the fluidized bed from which the reduction product of the fluidized bed reduction is taken as a metallized product.
  • the hydrocarbon-containing gas is preferably added in an amount of substance that corresponds to up to 25 mol%, preferably at least up to 15 mol% of the first reduction gas.
  • the process according to the invention for producing a metallized product from metal oxide-containing material it is carried out in at least two fluidized beds.
  • the metal oxide-containing material or, if applicable, the reduction product passes through these one after the other.
  • the method according to the invention for producing a metallized product from material containing metal oxide also includes adding at least one treatment gas to a fluidized bed.
  • a fluidized bed in which fluidized bed reduction takes place and/or to a fluidized bed in which no fluidized bed reduction takes place - because, for example, all of the particulate material introduced into the fluidized bed has already been reduced, i.e. is a reduction product.
  • the fluidized bed into which treatment gas is added is therefore a fluidized bed made of fluidized particles of material containing metal oxide and/or of fluidized particles of reduction product.
  • the treatment gas has no oxidizing capacity; it has a reducing effect on material containing metal oxide - preferably material containing iron oxide - and contributes to setting a reducing atmosphere in the fluidized bed. If the particulate material introduced into a fluidized bed supplied with treatment gas is still partially is oxidized, it can be reduced by the treatment gas, then fluidized bed reduction takes place in this fluidized bed, and the treatment gas is also another reducing gas, for example a second reducing gas. Preferably only the treatment gas is used to produce the fluidized bed by fluidizing particles, but other gases can also be used to contribute to the fluidization.
  • the first reducing gas is not to be classified as a treatment gas; the first reducing gas and the treatment gas are different gases.
  • a treatment gas entering a fluidized bed has a certain temperature, a certain pressure and a certain composition. Before this temperature, pressure and composition are present, a gas or a gas mixture that is a basis for producing the treatment gas is a precursor of the treatment gas.
  • At least one fluidized bed into which treatment gas is added is arranged after the fluidized bed or beds into which first reducing gas is added, as seen in the flow direction of the metal oxide-containing material as it passes through the fluidized beds in the course of the process.
  • the treatment gas comprises at least one hydrocarbon-containing gas with a proportion of at least 50 vol%.
  • the hydrocarbon-containing gas can be, for example, methane CH4 or a higher hydrocarbon or several higher hydrocarbons, or mixtures thereof; it can also be natural gas.
  • the metallized product of the process according to the invention is preferably taken from a fluidized bed into which treatment gas has been added. Such a metallized product contains carbon, preferably as cementite Fe3C in addition to dissolved carbon.
  • the treatment gas contributes to carburization; the fluidized bed into which it is introduced is also referred to as the carburizing fluidized bed in the context of this application.
  • the top gas emerging from the carburizing fluidized bed is referred to as the carburizing top gas in the context of this application.
  • carburizing top gas is taken from at least one carburizing fluidized bed and at least partially recirculated via a recirculation circuit into this carburizing fluidized bed and/or into another carburizing fluidized bed, wherein Combination with fresh gas containing hydrocarbons - i.e. gas that has not yet been used in a carburizing fluidized bed - such as methane CH4, higher hydrocarbons, natural gas - takes place.
  • fresh gas containing hydrocarbons - i.e. gas that has not yet been used in a carburizing fluidized bed - such as methane CH4, higher hydrocarbons, natural gas - takes place.
  • Treatment steps can also take place in the recirculation circuit, such as dedusting the carburizing top gas - wet or dry -, compression, heat exchange to heat another medium - for example the treatment gas, the first reducing gas, water or steam to generate steam or superheated steam -, heating of the recirculated gas stream.
  • a two-stage heating process For heating, it is preferable to carry out a two-stage heating process, with a first stage of convective heating up to a maximum temperature of 450°C and a second stage of heating to a temperature above 700°C using resistance heating or plasma burners or self-combustion after oxygen injection.
  • the critical temperature window of 450 - 700°C with regard to carbon deposition from carbon-rich gases and metal dusting is passed through more quickly than if convective heating were used to heat above 450°C.
  • water H2O can also be introduced into the gas circuit. This can be done before or after heating, or between the two stages; it is preferably done before heating.
  • a partial flow of the carburizing top gas - if necessary after one or more treatment steps - is used to prepare the first reducing gas.
  • a portion of the carburizing top gas - if necessary after one or more treatment steps - is used as fuel to heat a reducing gas precursor of the first reducing gas using a reducing gas furnace with a burner.
  • the calorific value of the carburizing top gas can be used energetically in the process, which improves the energy efficiency of the process.
  • the metallized product of the process according to the invention can be added to an EAF or a melting unit for further processing, for example to produce steel based on the metallized product. For this purpose, it is either fed in fine form directly or via an intermediate compaction unit.
  • the compaction step is completely isolated from the environment and air supply.
  • the compaction step has a gas circuit that consists only of inert gas components such as nitrogen N2.
  • oxygen is injected into the last fluidized bed reactor as seen in the gas flow direction and/or into the reducing gas supplied to the last fluidized bed reactor as seen in the gas flow direction in order to reduce or prevent magnetite formation in this fluidized bed reactor.
  • water can also be injected.
  • the reducing gas quality of the first reducing gas and/or the treatment gas is adjusted by adding water or water vapor to a reducing gas precursor of the first reducing gas and/or a precursor of the treatment gas. It is preferred to add water vapor to heated reducing gas precursors.
  • Steam for addition can be generated, for example, by indirect heat exchange with a hot gas stream present in the process. This can be, for example, carburizing top gas.
  • Heat content of carburizing top gas can also be used for other purposes in the process, for example to heat a precursor of the treatment gas.
  • the top gas of the fluidized bed reduction and/or the carburizing top gas is dedusted. This is preferably done by dry dedusting. However, it can also be done by wet dedusting.
  • the device also comprises a material feed device for feeding metal oxide-containing material into the fluidized bed unit, as well as a material removal device for removing metallized product from the fluidized bed unit.
  • the device also comprises a top gas discharge line for discharging top gas from the fluidized bed unit.
  • a top gas recirculation line is also present, which serves to feed top gas to the reducing gas addition line and optionally has treatment devices such as for example compressors, dust removal devices - for example for dry dust removal or wet dust removal -, heat exchangers.
  • the top gas recirculation line has an outlet branch through which a portion of the top gas can be discharged from the recirculation circuit if required.
  • the reducing gas addition line is used to guide reducing gas precursors of the first reducing gas or to guide the first reducing gas, and opens into the fluidized bed unit.
  • Addition lines for adding hydrogen and/or adding lines for adding nitrogen can open into the reducing gas addition line;
  • addition lines for adding other components of the first reducing gas can also open into the reducing gas addition line, such as top gas recirculation line, carburizing top gas line.
  • the at least two fluidized bed reactors are connected in series with respect to the flow of the metal oxide-containing material. According to one embodiment, they are also connected in series with respect to the gas flow, wherein the gas flow of the first reducing gas occurs in the opposite direction to the material flow.
  • Such a device is suitable for carrying out a method according to the invention.
  • the reducing gas supply line has a heating device. This serves to heat a
  • the heating device is preferably a device for electrical heating. Electrical heating can be, for example, a resistance heater or heating by a plasma produced using electrical energy.
  • the heating device is particularly preferably a device for electrical heating using plasma.
  • the heating device has, in addition to a device for electrical heating, one or more devices for heating.
  • a reducing gas furnace with burner is arranged in front of a device for electrical heating, as seen along the reducing gas addition line in the direction of the fluidized bed unit.
  • a heat exchanger is arranged upstream - as seen along the reducing gas addition line in the direction of the fluidized bed unit - of a device for electrical heating and/or upstream of another type of heating device.
  • the discharge branch opens into a fuel supply line for the reducing gas furnace.
  • a hydrocarbon addition line is present; this opens into the reducing gas addition line. It serves to add hydrocarbon-containing gas into the reducing gas addition line in order to prepare a hydrocarbon-containing reducing gas precursor of the first reducing gas. Preferably, it opens into the reducing gas addition line upstream of the heating device, as viewed in the direction of the fluidized bed unit.
  • a hydrocarbon feed line is present; this opens into a fluidized bed reactor of the fluidized bed unit. It serves to feed hydrocarbon-containing gas into the fluidized bed reactor. Preferably, it opens into the fluidized bed reactor for fluidized bed reduction, from which the reduction product of the fluidized bed reduction is taken as a metallized product.
  • hydrocarbon feed lines There may also be several hydrocarbon feed lines.
  • a treatment gas addition line is present; this opens into a fluidized bed reactor of the fluidized bed unit. It serves to add treatment gas to the fluidized bed reactor.
  • At least one carburizing stop gas line is present; such a line starts from a fluidized bed reactor with a treatment gas addition line. It preferably opens into the treatment gas addition line.
  • the carburizing stop gas line also opens into the reducing gas addition line.
  • the carburizing stop gas line also opens into a fuel supply line of a reducing gas furnace with burner.
  • a further subject of the present application is a signal processing device with a machine-readable program code, characterized in that it has control and/or regulating commands for carrying out a method according to the invention.
  • a further subject is a signal processing device for carrying out a method according to one of claims 1 to 8.
  • the signal processing device is part of a control and/or regulating system of a device for producing a metallized product from metal oxide-containing material.
  • a further subject matter of the present application is a machine-readable program code for a signal processing device - which is part of a control and/or regulation of a device for producing a metallized product from material containing metal oxide -, characterized in that the program code has control and/or regulation commands which cause the signal processing device to carry out a method according to the invention.
  • a further subject matter is a computer program product comprising commands for a signal processing device - which is part of a control and/or regulation of a device for producing a metallized product from material containing metal oxide - which, when the program for the signal processing device is executed, cause it to carry out the method according to one of claims 1 to 8.
  • a further subject matter of the present application is a storage medium with a machine-readable program code according to the invention stored thereon.
  • a further subject matter is a storage medium with a computer program stored thereon for carrying out a method according to one of claims 1 to 8.
  • a further subject matter of the present application is a control and/or regulation of a device for producing a metallized product from metal oxide-containing material with a computer containing a computer program product comprising instructions which, when the computer program is executed by the computer, cause the computer to carry out the steps of a method according to one of claims 1 to 8.
  • a further subject matter of the present application is a computer program product comprising instructions which, when the computer program is executed by a computer, cause the computer to carry out the steps of a method according to one of claims 1 to 8.
  • a further subject matter of the present application is a computer-readable data carrier on which such a computer program product is stored.
  • Figure 1 shows a device 10 for producing a metallized product 20 from metal oxide-containing material 30 using a first reducing gas. It comprises a fluidized bed unit 40 with four fluidized bed reactors 41, 42, 43, 44 and a reducing gas addition line 50 for adding the first reducing gas to the fluidized bed unit 40.
  • the four fluidized bed reactors 41, 42, 43, 44 are connected in series as a cascade of fluidized bed reactors with respect to the flow of the metal oxide-containing material 30. They are also connected in series with respect to the gas flow, with the gas flow of the first reducing gas occurring in the opposite direction to the material flow.
  • the device 10 also comprises a material feed device 60 for feeding metal oxide-containing material 30 into the fluidized bed unit 40, as well as a material removal device 70 for removing metallized product 20 from the Fluidized bed unit 40.
  • the device also includes a top gas outlet 80 for discharging top gas from the fluidized bed unit 40.
  • an optional top gas recirculation line 90 for supplying top gas to the reducing gas addition line 50. In the variant shown, this has treatment devices such as compressor 100 and dedusting device 110 - for example for wet dedusting.
  • the top gas recirculation line 90 has a discharge branch 120 through which a portion of the top gas can be discharged from the recirculation circuit if required.
  • the reducing gas addition line 50 opens into the fluidized bed unit 40.
  • a branch of the top gas recirculation line 90 also opens into the reducing gas addition line, so that top gas can be recirculated into the reducing gas circuit.
  • the device 10 is used to carry out a method for producing a metallized product 20 from metal oxide-containing material 30.
  • fluidized bed reduction of the metal oxide-containing material 30 takes place in the fluidized bed reactors 41, 42, 43, 44 using the first reducing gas.
  • the first reducing gas comprises hydrogen and nitrogen, the hydrogen content being at least 70 vol% and the nitrogen content being in a range from 5 vol% to 30 vol%.
  • the heating device is a reducing gas furnace with burner 150, which can be supplied with top gas as fuel from the top gas recirculation line 90 via the discharge branch 160 that opens into a fuel supply line for the reducing gas furnace.
  • Other fuels can also be used, these are supplied via corresponding addition lines; only one such addition line 170 is shown as an example.
  • the oxidizing agent - for example oxygen or oxygen-containing gas such as air - can be supplied via an optionally available oxidizing agent line 171.
  • the heating device could also be a device for electrical heating, which is not separately shown; this could operate without the supply of oxidizing agent or fuel.
  • Figure 2 shows largely analogous to Figure 1 , such as heating a reducing gas precursor of the first reducing gas before entering the fluidized bed partly by means of electrical Heating takes place in a device for electrical heating 180.
  • the electrical heating takes place in the gas flow direction after the reducing gas furnace 150 of the heating device.
  • Figure 3 shows largely analogous to Figure 2 , such as heating of a reducing gas precursor of the first reducing gas, which is carried out at least partially by means of heat exchange with top gas. Heating of a reducing gas precursor of the first reducing gas is carried out by indirect heat exchange with top gas before electrical heating or heating by means of a reducing gas furnace 150 with burner is carried out.
  • a heat exchanger 190a is installed in front of the device for electrical heating 180 and the reducing gas furnace 150 with burner, as seen along the reducing gas addition line 50 in the direction of the fluidized bed unit.
  • Figure 4 shows in to Figure 3 In a largely analogous representation, two variants of how hydrocarbon-containing gas can be introduced into the fluidized bed reduction. Both variants can be implemented individually or together.
  • a hydrocarbon addition line 200 - for example for the addition of natural gas - flows into the reduction gas addition line 50, in the example shown before heating steps.
  • a hydrocarbon feed line 210 - for example for feeding in natural gas - flows into a fluidized bed reactor of the fluidized bed unit; the opening into the fluidized bed reactor 44 for fluidized bed reduction is shown, from which the reduction product of the fluidized bed reduction is taken as a metallized product 20.
  • Figure 5 shows a variant of a device 220 for producing a metallized product 20 from metal oxide-containing material 30 using a first reducing gas. It comprises a fluidized bed unit 230 with four fluidized bed reactors 231, 232, 233, 240 and a reducing gas addition line 250 for adding the first reducing gas to the fluidized bed reactor 233 of the fluidized bed unit 230.
  • the four fluidized bed reactors 231, 232, 233, 240 are connected in series as a cascade of fluidized bed reactors with respect to the flow of the metal oxide-containing material 30. They are also connected in series with respect to the gas flow, with the gas flow of the first reducing gas from fluidized bed reactor 233 to fluidized bed reactor 231 taking place in the opposite direction to the material flow. The material flow takes place from fluidized bed reactor 231 in the direction of fluidized bed reactor 240.
  • the device 220 is used to carry out a method for producing a metallized product 20 from metal oxide-containing material 30. For this purpose, using the first Reducing gas fluidized bed reduction of the metal oxide-containing material 30 in the fluidized bed reactors 231,232,233.
  • a treatment gas addition line 260 opens into the fluidized bed reactor 240 of the fluidized bed unit 230. It serves to add treatment gas to the fluidized bed reactor 240.
  • the fluidized bed reactor 240 contains a fluidized bed of fluidized particles of reduction product of the fluidized bed reduction that took place by means of the first reduction gas in the fluidized bed reactors 231, 232, 233.
  • the treatment gas comprises at least one hydrocarbon-containing gas with a proportion of at least 50 vol%.
  • the metallized product of the process according to the invention is taken from the fluidized bed of the fluidized bed reactor 240.
  • This fluidized bed is a carburizing fluidized bed.
  • a carburizing top gas line 270 extends from the fluidized bed reactor 240 and opens into the treatment gas addition line 260.
  • Carburizing top gas is taken from the carburizing fluidized bed in the fluidized bed reactor 240 via this line and is at least partially recirculated into this carburizing fluidized bed via a recirculation circuit via its recirculation gas inlet section 280, combining with fresh hydrocarbon-containing gas - in the case shown, natural gas - which is provided via the natural gas supply line 290.
  • the recirculation circuit also shows the optional treatment steps of dedusting the carburizing top gas in the deduster 300 and compression in the compressor 310, heating the recirculated gas flow in the gas heater 320.
  • the deduster 300 can be a device for wet dedusting or a device for dry dedusting. If it is a device for dry dedusting, a heat exchanger can optionally be present in front of it for the purpose of cooling the carburizing top gas before dry dedusting.
  • a branch of the carburizing top gas line 270 also opens into the reducing gas addition line 250, which enables use of a partial flow of the carburizing top gas to prepare the first reducing gas.
  • Figure 6 shows largely analogous to the Figures 1 and 5 , such as carburizing top gas in addition to the Figure 5 shown use can also be used as fuel for a reduction gas furnace 330 with burner.
  • a branch of the carburizing gas line 270 - shown is a branch of this branch from its section recirculation line 280 - flows into a fuel supply line for the reduction gas furnace 330 with burner.
  • FIG. 6 Shown are optionally available water addition lines 340,341,342 for adding water and/or water vapor into reducing gas precursors of the first reducing gas or into precursors of the treatment gas.
  • Figure 7 shows an example of the origin of a reducing gas precursor of the first reducing gas using an excerpt from Figures 1 to 4 .
  • a reducing gas precursor is provided via a precursor feed line 350 and mixed with gas from the recirculation circuit via the top gas recirculation line 90.
  • hydrogen and nitrogen are subsequently added via the addition lines 130 and 140.
  • a steam reformer 360 a gas mixture is produced from natural gas 370 with steam 380, the carbon dioxide CO2 content of which is reduced in a CO2 separation device 390.
  • the gas mixture obtained in this way is provided as a reducing gas precursor of the first reducing gas via the precursor feed line 350.
  • a reducing gas precursor of the first reducing gas supplied analogously via a precursor feed line 350, can also come from other sources

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Dispersion Chemistry (AREA)
  • Manufacture And Refinement Of Metals (AREA)
EP23163719.0A 2022-11-30 2023-03-23 Réduction de lit fluidisé à base d'hydrogène Pending EP4379069A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP22210464 2022-11-30

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EP4379069A1 true EP4379069A1 (fr) 2024-06-05

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4410093C1 (de) * 1994-03-24 1995-03-09 Metallgesellschaft Ag Verfahren zur Direktreduktion von Eisenoxide enthaltenden Stoffen
WO1997013879A1 (fr) * 1995-10-10 1997-04-17 Voest-Alpine Industrieanlagenbau Gmbh Procede de reduction directe de materiau particulaire renfermant du fer et installation pour la mise en oeuvre dudit procede
US5882579A (en) * 1995-09-15 1999-03-16 Hylsa S.A. De C.V. Apparatus for producing direct reduced iron utilizing a reducing gas with a high content of carbon monoxide
DE19854632A1 (de) * 1997-12-05 1999-06-10 Voest Alpine Ind Anlagen Verfahren und Anlage zum Reduzieren von metalloxidhaltigem Material
EP3670676A1 (fr) * 2018-12-17 2020-06-24 Primetals Technologies Austria GmbH Procédé et dispositif de réduction directe à l'aide d'un gaz de réduction chauffé électriquement

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4410093C1 (de) * 1994-03-24 1995-03-09 Metallgesellschaft Ag Verfahren zur Direktreduktion von Eisenoxide enthaltenden Stoffen
US5882579A (en) * 1995-09-15 1999-03-16 Hylsa S.A. De C.V. Apparatus for producing direct reduced iron utilizing a reducing gas with a high content of carbon monoxide
WO1997013879A1 (fr) * 1995-10-10 1997-04-17 Voest-Alpine Industrieanlagenbau Gmbh Procede de reduction directe de materiau particulaire renfermant du fer et installation pour la mise en oeuvre dudit procede
DE19854632A1 (de) * 1997-12-05 1999-06-10 Voest Alpine Ind Anlagen Verfahren und Anlage zum Reduzieren von metalloxidhaltigem Material
EP3670676A1 (fr) * 2018-12-17 2020-06-24 Primetals Technologies Austria GmbH Procédé et dispositif de réduction directe à l'aide d'un gaz de réduction chauffé électriquement

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