Plant group and method for operating a plant group for steel production

Abstract

The invention relates to a steelmaking plant network comprising a converter steelworks (8) for crude steel production, a gas line system (13) connected at least to the converter steelworks (8) for receiving the exhaust gases generated during crude steel production, a chemical plant (14) and / or biotechnology plant connected to the gas line system (13), and wherein the gas line system (13) is connected to a hydrogen-carrying line (21) via a mixing device (33) arranged upstream of the chemical plant (14) or biotechnology plant in the direction of flow, the mixing device (33) being designed to enrich a supplied gas stream with hydrogen. According to the invention, a plant for hydrogen production is connected to the hydrogen-carrying line (21), which plant has an ammonia cracking plant (22) for cracking ammonia (23) into hydrogen and nitrogen, and a method for operating such a plant network.

Description

[0001] The invention relates to a plant network for steel production with a converter steelworks for crude steel production, a gas line system connected at least to the converter steelworks for receiving the exhaust gases which arise during crude steel production, with a chemical plant and / or biotechnology plant connected to the gas line system, and wherein the gas line system is connected to a hydrogen-carrying line via a mixing device arranged upstream of the chemical plant or biotechnology plant in the direction of flow, wherein the mixing device is designed to enrich a supplied gas stream with hydrogen.

[0002] In practice, there is a growing effort to produce steel in the most climate-friendly and CO2-free way possible. According to the methods commonly used to date, steel production takes place in a multi-stage process, during which iron ore is first reduced to pig iron in a blast furnace. For this purpose, the iron ore is fed into the blast furnace with additives as well as a large proportion of coke and possibly other reducing agents such as coal, oil, gas, biomass, processed all-plastics or other substances containing carbon and / or hydrogen, whereby the high carbon content reduces the iron to pig iron. At the same time, the carbon combines with the oxygen now released, so that the blast furnace top gas produced during the blast furnace process contains a high degree of CO2. Carbon monoxide, hydrogen and water vapor as well as a high proportion of nitrogen are also produced.Although the composition of the blast furnace top gas is subject to certain fluctuations, it typically contains between 20 and 30 vol.% CO, 20 to 30 vol.% CO 2 , 2 to 15% H 2 and 35 to 58% N 2 .

[0003] The blast furnace top gas is of comparatively low quality, particularly due to its high CO2 and N2 content. However, due to its high CO2 content, it can be used for heating purposes within the plant network.

[0004] Following pig iron production, the pig iron is converted into steel in a converter steelworks in a traditional metallurgical process. By injecting oxygen into the molten pig iron, harmful impurities such as carbon, silicon, sulfur, and phosphorus are removed. At the same time, the carbon content is reduced to the desired level. Because the oxidation processes generate significant heat, scrap is often added as a coolant in quantities of up to 25% of the pig iron. Lime is also added for slag formation and alloying agents.

[0005] A converter gas is withdrawn from the steel converter which has a high CO content. It also contains nitrogen, hydrogen and CO 2. A typical converter gas composition has 55 to 70 vol.% CO, 13 to 20 vol.% CO 2 , 2 to 10% H 2 and 0 to 30% N 2. In contrast to blast furnace top gas, the converter gas is of higher quality because the CO 2 and nitrogen content in particular are comparatively low and thus the converter gas can be converted to a large extent, for example thermally, due to the high CO content and the associated higher calorific value.

[0006] The production of methanol from blast furnace gas and / or converter gas is known from the prior art, e.g., in the form of EP 0 200 880 A2 or EP 3 080 308 B1. Nevertheless, practice has shown that chemical plants or biotechnology plants are often designed primarily to convert blast furnace top gas, since converter gas, due to its low inert gas content, is particularly well suited as an energy source for thermal conversion or for electricity generation. Furthermore, blast furnace top gas is primarily used for chemical conversion, since the high CO2 content in blast furnace top gas requires action to reduce CO2 emissions anyway.

[0007] Although various options for utilising the extracted waste gases in order to reduce the amount of CO2 released into the atmosphere have already been proposed within the framework of the classic smelting process, there is now a great effort in industry to prevent the amount of CO2 from being produced as far as possible. This can be achieved, for example, by using so-called direct reduction furnaces. In a direct reduction furnace, the reduction of iron ore to iron does not take place exclusively through the use of carbon in the form of coke, but rather through the use of hydrogen (H2). So that in the course of direct reduction, in addition to the reduced iron, mainly water vapor and a much smaller amount of CO2 are produced. Instead of hydrogen, natural gas or synthesis gas are also suitable for direct reduction. In the case of direct reduction with hydrogen, this can be obtained from water, for example, by electrolysis.Renewable energy sources are then a suitable energy source, allowing the reduction of iron ore in the most climate-friendly way possible. Since hydrogen from renewable sources is not yet available in large quantities, it is also possible to obtain hydrogen from natural gas, for example, through partial oxidation.

[0008] However, the increasing replacement of blast furnaces with direct reduction furnaces also means that blast furnace top gas is no longer available in sufficient quantities, resulting in supply gaps in existing chemical or biotechnology plants designed to accept blast furnace top gas that must be filled with other gases. Converter gas, in particular, is particularly suitable for use in chemical or biotechnology plants instead of thermal conversion. However, if converter gas is to be incorporated into an existing system, it is necessary to process this gas in such a way that a composition similar to that of blast furnace top gas is developed. To do this, the proportion of carbon dioxide and the proportion of nitrogen must be increased.However, hydrogen enrichment is also required for both blast furnace top gas and converter gas, as both gases have a very low hydrogen content.

[0009] The invention is therefore based on the object of specifying a plant network which enables the use of converter gas in a, in particular already existing, chemical plant and / or biotechnology plant.

[0010] The subject matter and solution to this problem is a plant network according to patent claim 1. Accordingly, a plant for hydrogen production is connected to the hydrogen-carrying line, which plant has an ammonia cracking plant for splitting ammonia into hydrogen and nitrogen.

[0011] The invention is based on the finding that the cracked gas formed in an ammonia cracking plant (ammonia cracker), which essentially consists of hydrogen and nitrogen, is particularly suitable for enabling a composition which approximately corresponds to that of the blast furnace top gas.

[0012] Ammonia is an extremely promising product that can bind large quantities of hydrogen in a chemically bound form and thus in a stable manner, making it easy to transport over long distances. For example, abroad, hydrogen can be produced using solar energy and water during water electrolysis, which is then further processed with nitrogen from the air to produce ammonia. This ammonia can then be transported, for example, via pipelines or transport ships and made available to the ammonia cracking plant of the plant network according to the invention. Within the ammonia cracking plant, the ammonia is cracked by incorporating heat, producing a cracking gas containing hydrogen and nitrogen in a ratio of between 2.5:1 and 3.5:1.This cracked gas can then be used to enrich the gases in the gas pipeline systems, especially the converter gas, with hydrogen.

[0013] There are two possible approaches to enrichment with fission gas. According to the first alternative, a hydrogen stream is separated from the fission gas. This can be achieved, for example, by pressure swing adsorption (PSA). Accordingly, a hydrogen stream and a residual fission gas stream are formed from the fission gas. During the separation, up to 70%, preferably up to 80%, of the hydrogen contained in the fission gas can be separated. Accordingly, the residual fission gas still contains 20-30% of the total hydrogen formed, which is now present in a mixture with the nitrogen. The separated hydrogen is then mixed with the converter gas or the exhaust gases in the gas line system via the gas line system and used, for example, for methanol synthesis. Since the converter gas is already of very high quality and only contains a small proportion of inert gas, such asnitrogen, it is possible to synthesize methanol in a very efficient manner.

[0014] Alternatively, it is also possible to add the cracked gas completely and without separating the hydrogen, whereby a significant proportion of nitrogen is added as an inert gas component. However, this allows the hydrogen produced in the cracking reaction to be utilized completely, not just up to 70% or 80%. Although this results in a comparatively inefficient process with regard to methanol synthesis, this can be at least partially offset by the higher hydrogen content. Consequently, the hydrogen-carrying line increases not only the hydrogen content of the mixture but also the nitrogen content of the converter gas.

[0015] The invention has recognized that when using cracked gas formed from ammonia, a ratio of the molar amounts of carbon dioxide to nitrogen is formed that corresponds to that of the blast furnace top gas. In particular, the molar ratio of CO 2 and CO to N 2 ((CO 2 +CO) / N 2 ) is in the range between 0.9 and 1.2.

[0016] Additionally, it may be necessary to increase the carbon dioxide content when adjusting the converter gas to the blast furnace top gas. Accordingly, a carbon dioxide-carrying line can also be connected to the gas pipeline system. Various options are available as a carbon dioxide source. A particularly preferred embodiment provides, for example, for a purge gas to be burned and the resulting carbon dioxide to be added via the carbon dioxide-carrying line.

[0017] Such purger gas is usually removed from the methanol synthesis cycle during methanol production and consists essentially of CO, H2, CO2, and N2. The removal of purger gas is necessary to prevent the unusable nitrogen content from accumulating excessively in the methanol synthesis cycle. At the same time, this purger gas can also be burned due to its CO and H2 content, and the thermal energy can be used for the ammonia cracker. If, according to the first variant, hydrogen is separated from the cracked gas, the residual cracked gas formed from H2 and N2 can also be burned, and the thermal energy can be used for the ammonia cracking plant.

[0018] The chemical plant is preferably a plant for producing methanol. For this purpose, a synthesis gas consisting essentially of CO and / or CO 2 and H 2 must be provided, which contains the components carbon monoxide and / or carbon dioxide and hydrogen in the correct ratio. This ratio is often described by the modulo (H 2 - CO 2 ) / (CO + CO 2 ) and is preferably in the range between 1.8 and 2.5, particularly preferably 2. Of course, it is also possible to produce other hydrocarbons within the framework of the chemical plant. The amount of hydrogen required for the production of the hydrocarbons is mainly provided by adding the cracking gas from the ammonia cracking during the course of adjusting the nitrogen concentration.In addition, the hydrogen content can also be adjusted by adding pure hydrogen from other sources, such as coke oven gas or hydrogen produced by water electrolysis.

[0019] If a biotechnology plant is planned in addition or as an alternative, it is preferably a fermentation plant, whereby the exhaust gases are used biochemically via fermentation and whereby products such as alcohols (ethanol, butanol), acetone or organic acids can be produced.

[0020] According to a further development of the invention, the converter gas is mixed with the ammonia cracking gas, and the gas is purified prior to conversion in the chemical or biotechnological plant. Accordingly, a gas purification device is connected to the gas pipeline system.

[0021] According to a further development of the invention, a blast furnace for pig iron production is additionally provided, wherein the blast furnace is connected to the gas pipeline system for receiving the exhaust gases generated during pig iron production. These exhaust gases are blast furnace top gas. As already explained above, it may be expedient to gradually convert existing steelworks to direct reduction using direct reduction furnaces, so that for a certain period of time, blast furnaces and direct reduction furnaces are used in parallel to produce pig iron. Accordingly, the plant network not only produces converter gas but also continues to produce blast furnace top gas, which also has a high carbon content and is therefore suitable for the production of chemical or biotechnological products.In particular, it is also known in this context that blast furnace top gas can be used to produce methanol, whereby the blast furnace top gas is either fed to a separate methanol production plant or whereby the blast furnace top gas is fed together with the converter gas to a methanol production plant.

[0022] According to a preferred embodiment of the invention, a melting unit for melting sponge iron is additionally provided, wherein the melting unit is connected to the gas line system for receiving the exhaust gases generated during melting.

[0023] In contrast to the traditional blast furnace process, direct reduction does not produce liquid pig iron, but rather a solid sponge iron, which must be melted to produce steel. This melting takes place in a melting unit.

[0024] Within the scope of the invention, the melting unit is preferably a so-called submerged arc furnace (SAF), in which only the sponge iron is melted. The actual steel production from the liquid pig iron then takes place in a subsequent step. Alternatively, the melting unit can also be an electric arc furnace, in which both the melting and the steel conversion take place. This is achieved by introducing the additives required for steel production into the electric arc furnace in addition to the sponge iron.

[0025] Regardless of the type of smelting unit, a molten gas is produced as exhaust gas during pig iron production in the smelting unit. This molten gas can fundamentally vary in its composition. However, it can be very similar to the converter gas and then has a composition of 60 to 95 vol.% CO, 4 to 9% CO 2 , 0 to 10 vol.% H 2 and 0 to 36 vol.% N 2 . Accordingly, it is a high-quality gas, but due to the high proportion of carbon-containing compounds, it is also considered a climate-damaging gas.

[0026] The sponge iron can, for example, be fed into the plant network in prefabricated form. Alternatively, a direct reduction furnace for producing sponge iron is also planned. In this case, it is conceivable that, despite the direct reduction furnace, a conventional steel plant power plant could continue to operate in parallel during a transitional phase. Both the pig iron produced in the blast furnace and the smelting unit would then be converted into crude steel, either together or separately, in converter steelworks.

[0027] Steelworks often also have a coking plant, which produces the coke required for the blast furnace directly on-site from coal. During the coke oven process, coke oven gas is produced in the coke oven, which has a hydrogen content of 55 to 70 vol. It also contains methane (CH4) in an amount of 20 to 30 vol., which can be easily converted to CO and H2 through partial oxidation. Accordingly, a coke oven can also be connected to the gas pipeline system via the hydrogen-carrying line.

[0028] In addition, the hydrogen production plant can also have an electrolysis plant for water electrolysis. In water electrolysis, water is split into hydrogen and oxygen by the introduction of electrical current. This type of design is particularly useful when electricity is available in large and inexpensive quantities. In this case, the electricity can be generated from renewable energy sources, such as solar energy or wind power. A large quantity of hydrogen is required just to operate the direct reduction furnace, so the hydrogen production plant can be connected to the gas pipeline system via the hydrogen-carrying line as well as to the direct reduction furnace. Furthermore, it is also conceivable in this context that the exhaust gases from the direct reduction furnace, after processing and, if necessary, cleaning, are fed to the hydrogen production plant orbe returned to the electrolysis plant so that hydrogen and oxygen can be recovered from the steam produced in the direct reduction furnace.

[0029] A further development of the invention further provides that the gas line system has a switchable gas collector configured to control the supply of the exhaust gases generated by the melting unit and / or the converter steelworks and / or the blast furnace. Such a configuration is particularly useful when a blast furnace is included, since the blast furnace top gases generated in the blast furnace differ significantly in composition from the exhaust gases in the melting unit and the converter steelworks. Such a switchable gas collector therefore makes it possible to control the composition of the exhaust gases conducted in the gas line system, so that conversions of varying efficiency can take place in the chemical plant or the biotechnological plant depending on the operating state.

[0030] Furthermore, it may also be advantageous if a power plant is connected to the gas pipeline system in addition to the chemical plant and / or biotechnology plant. In such a case, the gas pipeline system preferably has a switchable gas diverter that controls the supply of gas to the chemical plant or biotechnology plant and the power plant. For example, it is possible for the exhaust gases to be converted into electricity when electricity prices are high, while at low electricity prices they can be converted into electricity in the chemical plant or biotechnology plant.

[0031] The invention further relates to a method for operating a plant network, in particular a plant network according to the invention as defined in claim 9, with a converter steelworks for pig iron production, wherein a portion of a converter gas generated during crude steel production is first processed and, after processing, used to produce chemical or biotechnological products. In this context, a portion corresponds to a portion of the total amount of exhaust gas, but the portion and the total amount have an identical material composition.

[0032] According to the invention, a hydrogen-rich cracked gas can be obtained by splitting ammonia, with either the cracked gas directly or a hydrogen stream obtained from the cracked gas being added to the converter gas during processing to form a gas mixture. Additionally, the hydrogen stream can also be partially obtained from water by water electrolysis. At this point, it should be emphasized again that the process features already explained in connection with the plant combination also relate to the process according to the invention according to claim 8.

[0033] According to a further development of the invention, the converter gas is mixed with at least a portion of a melt gas produced during the melting of sponge iron. Accordingly, not only the converter gas but also a mixture of converter gas and melt gas is processed to form the gas mixture and, after processing, is used to manufacture chemical or biotechnological products.

[0034] In addition, at least a portion of the blast furnace top gas generated during pig iron production in the blast furnace can be processed separately from the converter gas or the gas mixture and, after processing, used to manufacture chemical or biotechnological products.

[0035] Alternatively or additionally, it is also possible to add the blast furnace gas to the gas mixture, in particular after processing, and to combine them and use them together to produce chemical or biotechnological products.

[0036] The chemical products are primarily methanol or other hydrocarbons. Methanol can be produced, for example, through methanol synthesis using a solid catalyst. Biotechnological products are primarily products produced by fermenting exhaust gases with the help of microorganisms.

[0037] The invention is explained in more detail below using exemplary embodiments. They show: Fig. 1 a schematic representation of a plant network with a blast furnace and a direct reduction furnace Fig. 2, 3 various possibilities for processing the converter gas for the production of chemical products.

[0038] The Figur 1 shows a schematic representation of a plant network with a so-called blast furnace route and a parallel direct reduction route. The direct reduction route has a direct reduction furnace 1, which is fed with iron ore 2 on the one hand and with a reducing agent 3 on the other hand, wherein the reducing agent 3 is hydrogen (H 2 ). During the direct reduction in the direct reduction furnace 1, an iron sponge 4 is formed from the iron ore 2 on the one hand, and a water vapor stream 5 is formed as exhaust gas on the other.

[0039] The sponge iron 4 is then melted in a melting unit 6 and the liquid pig iron 7 is converted into crude steel 9 in a downstream converter steelworks 8.

[0040] In the parallel blast furnace route, iron ore 2 and reducing agent 3, in this case coke, are fed into a blast furnace 10. Liquid pig iron 7 is immediately produced in the blast furnace 10, which is then converted into crude steel 9 in the downstream converter steelworks 8.

[0041] In contrast to the blast furnace 10, hydrogen is used in the direct reduction furnace instead of carbon as the reducing agent 3, so that essentially a water vapor stream 5 is formed as the exhaust gas. In contrast, a blast furnace top gas 11 is formed in the blast furnace, which is predominantly composed of carbon dioxide (CO 2 ) and carbon monoxide (CO). Furthermore, a not insignificant amount of nitrogen (N 2 ) is also present as an inert gas component, which is not available for further use of the blast furnace top gas 11.

[0042] In the melting unit 6 of the direct reduction route, an exhaust gas composed of several substances is also formed, which is referred to below as melt gas 12. Due to the comparatively low nitrogen content, this is a high-quality gas that can be fed to a chemical plant 14 via a gas pipeline system 13. In this chemical plant 14, the converter gas 15 and also the melt gas 12 can be converted, for example, during synthesis to methanol 32. Instead of the Fig. 1 However, a biotechnology plant is also conceivable for the chemical plant 14 shown.

[0043] In the Fig. 1 In the example shown, it is possible to mix the melt gas 12, the converter gas 15, and the blast furnace top gas 11. In addition, the gas mixture is also processed, which is represented by the processing device 17. The processing device 17 comprises all plant components and steps required to make the gas mixture usable for the conversion in the chemical plant 14. This processing device 17 is then Fig. 2 and 3 specified in more detail.

[0044] According to the Fig. 2 For the production of liquid pig iron 7, only a direct reduction furnace 1 for the production of sponge iron 4 and a melting unit 6 for the production of liquid pig iron 7 are now provided. The crude steel is produced in a converter steelworks 8 downstream of the melting unit 7.

[0045] As previously explained, iron ore 2 and a reducing agent 3 are fed to the direct reduction plant, the reducing agent 3 being hydrogen. This hydrogen can be formed in an electrolysis plant for water electrolysis 18. By supplying a steam stream 5 and incorporating electrical energy 19, the steam is split into hydrogen and oxygen, with the hydrogen then being fed to the direct reduction plant as reducing agent 3. Steam 5 is formed as exhaust gas in the direct reduction furnace 1 and can be fed back to the electrolysis plant 18.

[0046] The melt gas 12 from the melt gas unit 6 is then fed to a gas line system 13 and mixed with the converter gas 15 in a mixing device 33. The processing device 17 also initially provides for gas purification of the melt gas 12 and the converter gas 15 in a gas purification device 20. For methanol synthesis in the chemical plant 14, it is also necessary to supply hydrogen to the mixing device 33. For this purpose, the processing device 17 has a hydrogen-carrying line 21, which is connected to the mixing device 33 and the gas line system 13.

[0047] To produce the hydrogen, the processing device 17 has an ammonia cracking system 22, which cracks ammonia 23 into a cracked gas 24. This cracked gas 24 consists essentially of hydrogen and nitrogen in a ratio of 2.5:1 to 3.5:1. Hydrogen is then filtered out in a pressure swing adsorption system 25 and fed to the gas line system 13 via the hydrogen-carrying line 21, whereby the molten gas 12 is enriched with hydrogen. However, only a certain proportion of the hydrogen can be filtered out in the pressure swing adsorption system 25. This proportion is in the range of 70%. The remaining hydrogen, together with the nitrogen, is fed to a combustion system 27 as residual cracked gas 26. The heat 28 generated there can be used within the cracking system 22 to crack the ammonia 23.

[0048] The gas mixture 34 formed in the processing device 17 is then fed to the chemical plant 14.

[0049] The one in the Fig. 3 The system network shown corresponds largely to the system network according to the Fig. 2 agree.

[0050] Also according to the Fig. 3 An ammonia cracking plant 22 is provided, in which case the entire cracking gas 24 is fed to the gas line system 13 via the hydrogen-carrying line 21. Accordingly, the molten gas 12 is enriched not only with hydrogen but also with nitrogen. This increases the inert gas content in the molten gas 12. At the same time, however, the hydrogen contained in the cracking gas 24 can be fully utilized to enrich the gas mixture. This means that within the chemical plant 14, which is designed as a methanol synthesis plant, a so-called purge gas 29 must be removed, which has a high proportion of nitrogen but also of hydrogen and carbon monoxide. Accordingly, this purge gas 29 is suitable for combustion in an incineration plant 27. The resulting heat 28 can then be reused for the cracking plant 22.In addition, a carbon dioxide-containing stream 31 can be formed in a scrubbing device 30, which is fed to the gas line system 13.

[0051] Accordingly, according to the system diagram in the Fig. 3 not only hydrogen but also nitrogen and carbon dioxide are added to the gas mixture of converter gas 15 and melt gas 12. In particular, the last two components lead to the gas mixture being transformed in such a way that the composition corresponds to that of the blast furnace top gas 11. Accordingly, it may be useful to add the blast furnace top gas 11, after enrichment with hydrogen, to the processed gas mixture via a hydrogen-carrying line 21 and to convert them together in a chemical plant 14 to methanol 32. Such a configuration is particularly useful when, in a transition phase, both a blast furnace 10 and a direct reduction furnace 1 with a melting unit 6 are located at one location. According to the Fig. 3 In the embodiments shown, first a gas cleaning of the converter gas 15 and the melt gas 12 takes place and only then the addition of the fission gas 24.

[0052] Alternatively, it is also possible to purify the already formed gas mixture 34. This could also remove impurities in the fission gas 24.

Claims

1. A plant network for steel production comprising a converter steelworks (8) for crude steel production, a gas line system (13) connected at least to the converter steelworks (8) for receiving the exhaust gases generated during crude steel production, a chemical plant (14) and / or biotechnology plant connected to the gas line system (13), and wherein the gas line system (13) is connected to a hydrogen-carrying line (21) via a mixing device arranged upstream of the chemical plant (14) or biotechnology plant in the flow direction, the mixing device (33) being designed to enrich a supplied gas stream with hydrogen, characterized in that a hydrogen production plant is connected to the hydrogen-carrying line (21), which plant has an ammonia cracking plant (22) for splitting ammonia (23) into hydrogen and nitrogen.

2. System network according to claim 1, characterized in thatin addition, a blast furnace (10) is provided for the production of pig iron, wherein the blast furnace (10) is connected to the gas line system (13) for receiving the exhaust gases which arise during the production of pig iron.

3. System according to claim 1 or 2, characterized in that in addition, a melting unit (6) is provided for melting sponge iron (4), wherein the melting unit (6) is connected to the gas line system (13) for receiving the exhaust gases which arise during melting.

4. System network according to claim 3, characterized in that In addition, a direct reduction furnace is provided for the production of sponge iron (4).

5. System according to one of claims 2 to 4, characterized in that the gas line system (13) has a switchable gas collector which is designed to control the supply of the exhaust gases generated by the melting unit (6) and / or the converter steelworks (8) and / or the blast furnace (10).

6. Plant combination according to one of claims 1 to 5, characterized in that the chemical plant (14) is a methanol production plant.

7. System according to one of claims 1 to 6, characterized in that the hydrogen production plant additionally comprises an electrolysis plant (18) for water electrolysis.

8. System according to one of claims 1 to 6, characterized in that the gas line system (13) is connected to a carbon dioxide-carrying line.

9. A method for operating a plant network, in particular according to one of claims 1 to 8, with a converter steelworks (8) for crude steel production, wherein at least a portion of a converter gas (15) arising during crude steel production is processed and, after processing, is used for the production of chemical or biotechnological products, characterized in thatby splitting ammonia (23) a hydrogen-rich cracked gas (24) is obtained and wherein the cracked gas (24) or a hydrogen stream obtained from the cracked gas (24) is fed to the converter gas (15) during the processing to form a gas mixture (34).

10. Method according to claim 9, characterized in that to form the gas mixture (34) at least a partial amount of a melting gas (12) produced during the melting of sponge iron (4) is added.

11. Method according to claim 9 or 10, characterized in that at least a portion of a blast furnace top gas (11) arising during pig iron production in the blast furnace (10) is processed separately from the converter gas (15) and, after processing, is used for the production of chemical or biotechnological products.

12. Method according to claim 11, characterized in that to form the gas mixture (34) the blast furnace top gas (11) is added.

13. Method according to one of claims 9 to 12, characterized in that Converter gas (15) is enriched with a CO2-containing gas.

14. Method according to one of claims 9 to 13, characterized in that the gas mixture (34) is purified before the production of chemical or biotechnological products.

Images