阅读说明：本技术 用于操作冶金炉的方法 (Method for operating a metallurgical furnace ) 是由 克里斯蒂亚诺·卡斯塔尼奥拉 洛伦佐·米切列蒂 于 2020-05-13 设计创作，主要内容包括：本发明涉及用于操作冶金炉(10)的方法。为了提供为冶金炉提供合成气体的简化的方式,本发明提供了方法包括：-在冶金炉(10)外部通过含碳材料(41)与富氧气体(40)一起燃烧来执行燃烧过程以产生废气(42),该废气(42)是含CO-(2)的气体；-在废气由于燃烧过程而具有燃烧引起的升高的温度时,废气(42)与含碳氢化合物的燃料气体(43)结合,以获得具有比重整过程、优选地干式重整过程所需的重整温度高的温度的第一气体混合物(44)；-使第一气体混合物(44)经历重整过程,从而产生包含CO和H-(2)的合成气体(45),重整过程以非催化的方式进行；以及-将合成气体(45)给送到冶金炉(10)中。(The invention relates to a method for operating a metallurgical furnace (10). In order to provide a simplified way of providing synthesis gas to a metallurgical furnace, the invention provides a method comprising: -performing a combustion process outside the metallurgical furnace (10) by combusting carbonaceous material (41) together with oxygen-enriched gas (40) to produce exhaust gas (42), the exhaust gas (42) being CO-containing 2 The gas of (4); -combining the exhaust gas (42) with a hydrocarbon-containing fuel gas (43) to obtain a first gas mixture (44) having a higher temperature than the reforming temperature required for the reforming process, preferably the dry reforming process, when the exhaust gas has a combustion-induced elevated temperature due to the combustion process; -subjecting the first gaseous mixture (44) to a reforming process, thereby producing a gas comprising CO and H 2 The reforming process being carried out in a non-catalytic manner; and-feeding the synthesis gas (45) into the metallurgical furnace (10).)

1. A method for operating a metallurgical furnace (10), the method comprising:

-performing a combustion process outside the metallurgical furnace (10) by combusting carbonaceous material (41) with oxygen-enriched gas (40) to produce an exhaust gas (42), the exhaust gas (42) being CO-containing₂The gas of (4);

-combining the exhaust gas (42) with a hydrocarbon-containing fuel gas (43) to obtain a first gas mixture (44) when the exhaust gas has a combustion-induced elevated temperature due to the combustion process, the first gas mixture (44) having a temperature higher than a reforming temperature required for a reforming process;

-subjecting the first gas mixture (44) to the reforming process, thereby producing a gas mixture comprising CO and H₂The reforming process being carried out in a non-catalytic manner; and

-feeding the synthesis gas (45) into the metallurgical furnace (10).

2. Method according to claim 1, characterized in that said oxygen-enriched gas (40) comprises at least 60% O₂Preferably, the oxygen-enriched gas (40) comprises at least 80% O₂More preferably, the oxygen-enriched gas (40) comprises at least 90% O₂。

3. The method according to any of the preceding claims, wherein the exhaust gas (42) has a combustion-induced temperature above 1000 ℃ when combined with the fuel gas (43), preferably the exhaust gas (42) has a combustion-induced temperature above 1500 ℃ when combined with the fuel gas (43), more preferably the exhaust gas (42) has a combustion-induced temperature above 2000 ℃ when combined with the fuel gas (43).

4. The method according to any of the preceding claims, characterized in that the fuel gas (43) has a temperature below 100 ℃ when combined with the exhaust gas (42).

5. The method according to any one of the preceding claims, characterized in that the exhaust gas (42) and the fuel gas (43) are brought together as CO-containing₂To obtain the first gas mixture (44).

6. The method according to any of the preceding claims, characterized in that the carbonaceous material (41) comprises tar, coke breeze, charcoal, coal and/or heavy fuel oil.

7. Method according to any of the preceding claims, wherein the fuel gas (43) comprises natural gas, coke oven gas and/or biogas.

8. The method according to any of the preceding claims, wherein the synthesis gas (45) immediately after the reforming process has a post-reforming temperature above 1000 ℃, preferably the synthesis gas (45) immediately after the reforming process has a post-reforming temperature above 1200 ℃, more preferably the synthesis gas (45) immediately after the reforming process has a post-reforming temperature above 1500 ℃.

9. The method according to any of the preceding claims, characterized in that the metallurgical furnace (10) is a shaft furnace.

10. The method according to any of the preceding claims, characterized in that the metallurgical furnace (10) is a blast furnace.

11. The method according to claim 10, characterized in that the synthesis gas (45) is fed into the blast furnace (10) at the tuyere level (10.1).

12. Method according to claim 10, characterized in that the synthesis gas (45) is fed into the blast furnace (10) at a shaft level (10.2) higher than the tuyere level (10.1).

13. A method according to any of the preceding claims, characterized in that the synthesis gas (45) is fed into the metallurgical furnace (10) together with an additive gas (46) having a temperature lower than the post-reforming temperature of the synthesis gas, wherein the additive gas (46) is CO-and/or H-containing₂The gas of (2).

14. A method according to claim 13, characterized in that the synthesis gas (45) is mixed with the additive gas (46) to form a second gas mixture (47) before feeding the synthesis gas (45) into the metallurgical furnace (10).

15. The method according to claim 14, wherein the second gas mixture (47) has a temperature between 700 ℃ and 1200 ℃, preferably the second gas mixture (47) has a temperature between 800 ℃ and 1100 ℃.

16. A method according to any one of the preceding claims, wherein the synthesis gas (45) is obtained by a dry reforming process or a wet reforming process.

Technical Field

The present invention relates to a method for operating a metallurgical furnace.

Background

Blast furnaces today represent the most widely used method for steel production, despite alternative methods, such as scrap melting or direct reduction in electric arc furnaces. One of the concerns of blast furnace plants is the discharge of blast furnace gases from the blast furnace. This gas is also commonly referred to as "top gas" because it exits the blast furnace at the top of the furnace. Although at an early stage such blast furnace gas could be allowed to vent directly into the atmosphere, this has long been considered a waste of resources and an undue burden on the environment. One component of the blast furnace gas is CO₂，CO₂Are environmentally hazardous and are largely useless for industrial applications. In practice, the blast furnace gas exiting the blast furnace typically includes CO at concentrations of up to 20% to 30%₂. In addition to this, blast furnace gases usually comprise considerable amounts of N₂、CO、H₂O and H₂. However, N₂The content depends mainly on whether hot air or (pure) oxygen is used for the blast furnace.

To reduce CO₂As emissions, it has been proposed to reform blast furnace gas to obtain synthesis gas (also referred to as syngas) which can be used for a variety of industrial purposes. According to the most common reforming process, the blast furnace gas is mixed with a gas mixture comprising at least one hydrocarbon (e.g. CH)₄And possibly higher molecular weight hydrocarbons) is mixed. In the so-called dry reforming reaction, hydrocarbons of the fuel gas and CO in the blast furnace gas₂Reaction for the production of H₂And CO. In the so-called wet reforming reaction, the hydrocarbons react with H in the blast furnace gas₂The O reaction is also used to form H₂And CO. In either way, H is obtained with a significant increase in concentration₂And CO. It is also proposed to use this synthesis gas as a reducing gas, which can be recycled, i.e. reintroduced into the blast furnace. According to one method, the synthesis gas is fed into the blast furnace together with oxygen-enriched hot air (i.e. hot air) and pulverized coal. This type of furnace may also be referred to as a "syngas blast furnace".

Another potential use of synthesis gas is in combination with the objective of increasing the amount of auxiliary fuel (e.g. pulverized coal) entering the blast furnace at the tuyere level. Doing so requires increasing the oxygen content in the hot blast and, in connection therewith, reducing the hot blast velocity. This in turn leads to an undesirable reduction in the top gas temperature. This effect can be counteracted by means of a hot gas, in particular a hot reducing gas, shaft injection (draft injection). Synthesis gas as described above may be used for this purpose. However, although synthesis gas generation using, for example, blast furnace gas may be achieved as described, for example, in WO 2019/057930 a1, the reforming process is endothermic and therefore requires substantial heating of the blast furnace gas and/or fuel gas. In some cases, a catalyst is required to support the reforming process. The heating adds complexity to the reforming process and also requires fuel consumption for burners and the like, partly offsetting (undoing) the CO achieved by the top gas recycle₂And (4) reducing.

Disclosure of Invention

It is therefore an object of the present invention to provide a simple way of providing synthesis gas to a metallurgical furnace. This object is solved by a method according to claim 1.

The present invention provides a method for operating a metallurgical furnace. In a first step, a combustion process is performed outside the metallurgical furnace by combusting carbonaceous material together with oxygen-rich gas to produce off-gas (offgas), which is CO-containing₂The gas of (2). The carbonaceous material may be solid, liquid and/or gaseous. The carbonaceous material may also be a mixture of different chemical species containing carbon. Usually, carbon is not included in elemental form, but as part of a compound, for exampleSuch as part of a hydrocarbon. In particular, the carbonaceous material may include tar, coke breeze, charcoal, coal, and/or heavy fuel oil. During combustion, the carbonaceous material is combusted, i.e. burned, by the oxygen-enriched gas. The oxygen-enriched gas is typically O having a significant ratio to air₂High concentration of O₂A concentration of gas. Typically, the oxygen-enriched gas comprises mainly O₂I.e. the oxygen-enriched gas has more than 50% O₂And (4) concentration. Preferably, the oxygen-enriched gas comprises at least 60% O₂Preferably at least 80% O₂More preferably at least 90% O₂. In some cases, the oxygen-enriched gas may even be referred to as "oxygen", although it is understood that the concentration is low (e.g., as<5%) of other components such as N₂It is almost unavoidable. The product of the combustion process is a mixture comprising CO₂Of the exhaust gas of (1). It is understood that the exhaust gas may contain other components, such as H₂O, CO and unreacted components of the carbonaceous material and/or the oxygen-enriched gas. However, CO₂The content may be relatively high, for example above 30%. The combustion process is performed outside the metallurgical furnace, i.e. the combustion process is not part of the internal process inside the metallurgical furnace. However, the combustion process may be performed in a reactor close to the metallurgical furnace. The use of oxygen-enriched gas to combust the carbonaceous material may result in very high flame temperatures, for example above 2000 ℃, 2500 ℃ or even 3000 ℃.

In a further step, the exhaust gas is combined with a hydrocarbon-containing fuel gas to obtain a first gas mixture having a higher temperature than the reforming temperature required for the reforming process, preferably the dry reforming process, when the exhaust gas has a combustion-induced elevated temperature due to the combustion process. The fuel gas may, for example, comprise Coke Oven Gas (COG), natural gas and/or biogas. In particular, the fuel gas may comprise a mixture of any of these gases. The fuel gas usually has a high concentration of low molecular hydrocarbons, in particular CH₄. In the first gas mixture, the exhaust gas and the fuel gas may be mixed more or less well. Combining the exhaust gas with the fuel gas generally refers to "allowing the exhaust gas to mix with the fuel gas". This can be doneTo include (actively) mixing the exhaust gas with the fuel gas, i.e. applying mechanical forces to mix the gases. However, in some cases it may be sufficient, for example, to inject the two gases into the container such that mixing occurs more or less passively by convection and/or diffusion. However, it will be appreciated that the chemical reaction is enhanced by a higher degree of mixing. Combining the exhaust gas with the fuel gas to obtain the first gas mixture comprises the possibility of combining only the exhaust gas and the fuel gas and also at least one further gas for the first gas mixture. The (at least) two gases may be combined in a dedicated vessel, which may be referred to as a mixing vessel or mixing chamber. When the exhaust gas has an elevated temperature due to the combustion process, which elevated temperature is referred to herein as the combustion-induced temperature, the exhaust gas combines with the fuel gas. The combustion-induced temperature is of course due to the highly exothermic nature of the combustion process. When the exhaust gas is combined with the fuel gas, the gas mixture thus also has a higher temperature than the reforming temperature required for the reforming process, preferably for the dry reforming process. The dry reforming process, which will be described hereinafter, requires that the first gas mixture have a certain minimum temperature, which is referred to herein as the reforming temperature. If the first gas mixture has at least this reforming temperature, the reforming process is advantageously started and continued without the need for a catalyst or additional heating.

In a further step of the process, the gas mixture is subjected to a (preferably dry) reforming process, thereby producing a gas mixture comprising CO and H₂The synthesis gas of (2). The chemical mechanism of the dry reforming process is not limited within the scope of the present invention, but generally includes at least the CO of the exhaust gas₂The content reacts with hydrocarbons in the fuel gas, for example according to the following reaction: CO 2₂+CH₄→2H₂+2 CO. This is commonly referred to as dry reforming. In addition to this, H of the exhaust gas₂The O content (if present) may react with hydrocarbons in the fuel gas, for example according to the following reaction: h₂O+CH₄→3H₂+ CO. This may also be referred to as wet reforming. The dry reforming process requires an elevated reforming temperature, depending on how muchFactors such as the presence or absence of catalyst. Without a catalyst, the reforming temperature should be, for example, higher than 800 ℃ and may preferably be between 900 ℃ and 1600 ℃. Because the temperature due to combustion of the exhaust gas is high enough to start up and maintain the dry reforming process once the exhaust gas is combined with the fuel gas, the dry reforming process can be performed in the same vessel as the vessel in which the gases are combined (or mixed). It should be noted that the dry reforming process may be performed at elevated pressures. This may be caused, inter alia, by not allowing the exhaust gases to expand after the combustion process. Advantageously, the (preferably dry) reforming process is carried out without the need for a catalyst. In other words, the reforming process is carried out in a non-catalytic manner. Another advantage of the present invention is that it reduces the need and cost for reformate gas purification. In fact, since no catalyst is used, there is no need to remove catalyst poisons from the reformate gas before the reformate gas is used in any other process.

It should be noted that although at least some of the exhaust gas needs to be mixed with some of the fuel gas to start the reforming process, the mixing and reforming may occur at least partially simultaneously. In fact, this is often the case because the reforming process is initiated by the elevated temperature caused by the combustion of the exhaust gases.

In another step of the method, the synthesis gas is fed into a metallurgical furnace. As will be explained below, this includes the possibility that the synthesis gas is mixed with another gas before being fed into the metallurgical furnace, i.e. the synthesis gas may be fed into the metallurgical furnace as part of the gas mixture. In most cases, synthesis gas is used as the reducing gas in the metallurgical furnace.

A significant advantage of the process of the present invention is that the process uses the heat generated by the exothermic combustion process to start and maintain a (preferably dry) reforming process. It can also be said that the (preferably dry) reforming process is driven efficiently by the high flame temperature of the combustion process. This simplifies the process and eliminates the need for additional heating of the gas mixture and/or the presence of a catalyst.

The exhaust gas, when combined with the hydrocarbon containing gas, may have a relatively high temperature, which is referred to herein as a combustion induced temperature, because the temperature is generated by exothermic combustion and occurs after the combustion. In particular, the temperature induced by combustion may be higher than 1000 ℃, preferably higher than 1500 ℃, more preferably higher than 2000 ℃. These temperatures are generally sufficient to start and maintain the reforming process. It will be appreciated that this also depends on the ratio between the exhaust gas and the hydrocarbon containing gas and the temperature of the hydrocarbon containing gas.

The reforming process may be supported by heating the fuel gas, for example to a temperature above 500 ℃, prior to combining the fuel gas with the exhaust gas. However, due to the high temperatures caused by combustion, relatively "cold" fuel gas may be used. More specifically, the fuel gas may have a temperature of less than 100 ℃ when combined with the exhaust gas. In particular, the fuel gas may have an ambient temperature, i.e. between 15 ℃ and 40 ℃.

Alternatively, the exhaust gas and the fuel gas may be mixed as a CO-containing gas₂To form a first gas mixture. The make-up gas may be considered a supplement to the exhaust gas, as the make-up gas will also be CO₂Is added to the gas mixture. A variety of sources are available for make-up gas. For example, the make-up gas may be blast furnace top gas and/or basic oxygen furnace gas and/or carbon capture gas produced by a carbon capture device. As is known in the art, the carbon capture device will contain CO₂To have reduced CO₂A first part of the content and with an increased CO₂A second fraction of the amount. A second portion, referred to herein as the carbon capture gas, may be used as the make-up gas. For example, a carbon capture device for processing coke oven gas may be used as a source of carbon capture gas. However, if a supplementary gas is used as a component of the first gas mixture, this generally reduces the temperature of the first gas mixture, since for example the temperature of the carbon capture gas is significantly lower than the temperature caused by the combustion of the exhaust gas. Therefore, the proportion of make-up gas must be adjusted to maintain the temperature of the first gas mixture above the reforming temperature. The make-up gas may be at ambient temperatureLower or may alternatively be preheated to a temperature of up to 500 c. Preheating will further increase the volume of make-up gas available for use in the process.

As mentioned above, the temperature caused by the combustion of the exhaust gas may be higher than 2000 ℃. Typically, even if the fuel gas has been heated before being combined with the exhaust gas, the resulting gas mixture has a (average) temperature that is lower than the combustion-induced temperature. Furthermore, the (preferably dry) reforming process is an endothermic reaction that results in a reduction in temperature. However, the temperature of the resulting synthesis gas, which may be referred to as the post-reforming temperature, may still be very high. The synthesis gas may have a post-reforming temperature of more than 1000 ℃, preferably more than 1200 ℃, more preferably more than 1500 ℃ immediately after the reforming process. This means that the post-reforming temperature may be too high to be introduced immediately into the metallurgical furnace. This of course depends on the type of metallurgical furnace and the location where the synthesis gas is fed into the metallurgical furnace. Generally, any disturbance of the temperature distribution within the metallurgical furnace will be avoided.

According to one embodiment, the metallurgical furnace is a shaft furnace (draft furnace). Such shaft furnaces may be used, for example, for producing direct reduced iron using the Midrex or HYL process, or for producing hot briquetted iron. In particular, the metallurgical furnace may be a blast furnace. The overall setup and operating principles of blast furnaces are known in the art and will therefore not be described in detail here. There are several options as to where the synthesis gas may be introduced into the blast furnace.

According to one option, the synthesis gas is fed into the blast furnace at the tuyere level. The tuyere level corresponds to the melting zone of the blast furnace, for which a temperature between 1400 ℃ and 1800 ℃ is characteristic. At the tuyere level, even post-reforming temperatures of the synthesis gas above 1500 ℃ are harmless and the synthesis gas can be fed directly into the blast furnace.

According to another option, the synthesis gas is fed into the blast furnace at a shaft level (draft level) higher than the tuyere level. The shaft level corresponds primarily to the reduction zone of the blast furnace, which generally has a temperature significantly lower than the melting zone. For example, the temperature at the level of the shaft may be between 800 ℃ and 1100 ℃. This is mainly lower than the post-reforming temperature of the synthesis gas. The immediate introduction of hot synthesis gas at the level of the shaft has an adverse effect on the temperature distribution in the blast furnace. It will be appreciated that the synthesis gas is cooled down to a sufficiently low temperature. However, cooling corresponds to an undesirable loss of energy. Nevertheless, it will be appreciated that the heat lost in the cooling process is used in the heat exchanger, for example to heat the fuel gas before it combines with the exhaust gases.

It should be noted that if the synthesis gas is fed into the blast furnace at the level of the shaft, other gases and/or solids are fed into the blast furnace at the level of the tuyeres. In this respect, there is no limitation in the scope of the present invention. In particular, the auxiliary fuel can be introduced at the tuyere level. One option is to feed the pulverized coal into the blast furnace together with oxygen-enriched gas at the tuyere level. This method, also known as Pulverized Coal Injection (PCI), is primarily known in the art. Another option is for the catalyst to contain hydrocarbons, such as CH₄Is sprayed with a gas such as natural gas, CO and/or H₂. Generally, it is desirable to increase the amount of auxiliary fuel injected at the tuyere level, which requires increasing the oxygen content in the hot blast and reducing the hot blast rate. This in turn can reduce the top gas temperature to an undesirable level. However, if hot reducing gas, such as synthesis gas provided by the process of the invention, is introduced above the tuyere level, a reduction of the top gas temperature can be prevented or at least limited.

In this context, it should be noted that reducing the gas flow through the blast furnace significantly reduces the risk of certain irregularities, such as spillage or drooling and slipping. Injection of synthesis gas at the level of the shaft has a beneficial effect on the productivity of the blast furnace, since it allows to reduce the gas flow while maintaining a sufficiently high top gas temperature.

A preferred option to avoid any energy loss due to cooling is to feed the synthesis gas to the metallurgical furnace together with an additive gas (additive gas) having a temperature lower than the post-reforming temperature of the synthesis gas, the additive gas being CO-containing and/or H-containing₂The gas of (2). In other words, the gas is addedAnd the composition of the synthesis gas at least partly correspond to each other in that both the additive gas and the synthesis gas contain CO and/or H₂. Thus, the additive gas may also be used as a reducing gas in the metallurgical furnace. For example, all steelmaking gases can be used as additive gases, such as blast furnace gas, basic oxygen furnace gas, or other gases. Even if gaseous CO and/or H is added₂The content may be very low, but the proportion of such "cooling gas" in the mixture with synthesis gas is usually limited and the dilution effect is acceptable. This embodiment may be used in particular if the metallurgical furnace is a blast furnace and synthesis gas is fed into the metallurgical furnace at the level of the furnace shell. The average temperature of the synthesis gas and the additive gas is of course lower than the post-reforming temperature of the synthesis gas, so that detrimental effects on the temperature distribution in the blast furnace can be avoided. It should be noted that the additive gas may also be synthesis gas produced by a separate reforming process. This may even be a reforming process using blast furnace gas, for example.

One possible consideration is to introduce the forming gas and the additive gas separately into the metallurgical furnace, but in the same area of the metallurgical furnace. To some extent, the synthesis gas and the additive gas may be mixed in the metallurgical furnace prior to reaction. However, the separate introduction of the two gases results in a temperature difference which locally alters the process in the metallurgical furnace. In this case, the synthesis gas may locally heat a part of the metallurgical furnace, while the additive gas cools a part of the metallurgical furnace, which is harmful to a large extent. It is therefore preferred that the synthesis gas is mixed with the additive gas before it is fed into the metallurgical furnace. This results in a second gas mixture of the two gases having a temperature between the temperature after reforming and the temperature of the additive gas before mixing. In particular, the resulting second gas mixture may have a temperature between 700 ℃ and 1200 ℃, preferably between 800 ℃ and 1100 ℃. This temperature range facilitates feeding the blast furnace at the level of the shaft. Mixing the gases and introducing the mixture into the metallurgical furnace simplifies the design of the injection system, in addition to resulting in a more uniform temperature distribution.

Drawings

Preferred embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of a blast furnace plant for carrying out an embodiment of the method of the present invention; and

fig. 2 is a schematic view of a part of the blast furnace plant from fig. 1.

Detailed Description

Fig. 1 schematically shows a blast furnace installation 1 comprising a blast furnace 10. At the top end of the blast furnace 10, the blast furnace 10 typically receives coke 12 and ore 13 from a silo 15. At the bottom end of the blast furnace 10, pig iron and slag are extracted (not shown for simplicity). The operation of the blast furnace 10 itself is well known and will not be described further herein. At the top end, blast furnace gas 14 is recovered from the blast furnace 10. The recovered blast furnace gas 14 may be treated in a gas cleaning facility 20 to primarily remove particulate matter from the blast furnace gas 14 and may condense a portion of the vapors contained in the blast furnace gas 14, the recovered blast furnace gas 14 may, for example, have a concentration of N below 40%₂CO and CO at a concentration of about 25% to 40%₂And about 5% to 15% H₂. The recovered and cleaned blast furnace gas 14 may be used for various purposes, which are not shown in detail herein. After cleaning the blast furnace gas 14, the CO of the blast furnace gas₂The content may be reduced in the carbon trap device 21. Here, a part of the blast furnace gas is separated into a carbon capture gas 22, which is a gas having a high concentration of CO₂E.g. CO in a concentration of more than 50% or more than 70%₂The gas of (2). The carbon capture gas 22 or a portion of the carbon capture gas may be used as the make-up gas 48.

In the lower part of the blast furnace 10, i.e. at the tuyere level 10.1, the blast furnace 10 receives pulverized coal 26 and hot blast air 27, which is supplied from a hot furnace installation 25 comprising a plurality of hot blast stoves. The hot air 27 may comprise air or oxygen-enriched air. Alternatively, at the tuyere level, the blast furnace may receive cold oxygen-containing gas with a concentration of typically 95%, so that for the most partOr completely replace the hot air. Another option is to include CO and/or H₂Is injected with hot and/or cold oxygen-containing gas and pulverized coal.

At a shaft level 10.2 above the tuyere level 10.1, the blast furnace 10 receives a mixture 47 of synthesis gas 45 and additive gas 46. Synthesis gas 45 is produced in the synthesis gas reactor 30, which is schematically shown in fig. 2. The syngas reactor 30 includes a combustor 31 supplied with oxygen-enriched gas 40 and carbonaceous material 41. The oxygen-enriched gas 40 may comprise at least 90% O₂While the carbonaceous material 41 may, for example, include tar, coke breeze, charcoal, coal, and/or heavy fuel oil. During combustion, carbonaceous material 41 is combusted in the combustor 31 with oxygen-enriched gas 40, thereby producing an exhaust gas 42, which may have, for example, 80% CO₂、15％H₂O and 5% N₂. Due to the strongly exothermic combustion process, the flame temperature may be higher than 3000 ℃. The exhaust gas 42 and the fuel gas 43 are injected into the mixing portion 32 where the exhaust gas 42 and the fuel gas 43 are mixed. The fuel gas 43 is a hydrocarbon-containing gas, such as coke oven gas, natural gas and/or biogas. When the exhaust gas 42 is combined with the fuel gas 43, the exhaust gas has a combustion induced temperature of at least 2000 ℃, while the fuel gas 43 may have a temperature below 100 ℃, e.g., ambient temperature. The fuel gas 43 and the exhaust gas 42 form a first gas mixture 44 having a higher reforming temperature than is required for the reforming process, preferably a dry reforming process. The reforming temperature should be above 800 ℃ and may preferably be between 900 ℃ and 1600 ℃. Due to the high temperature of the first gas mixture 44, which in turn is mainly due to the temperature caused by the combustion of the exhaust gas 42, the reforming process starts without additional heating or application of a catalyst. Alternatively, a supplemental gas 48 may be added to the fuel gas 43 and the off-gas 42 to form the first gas mixture 44, such supplemental gas 48 may be, for example, a blast furnace gas and/or a basic oxygen furnace gas and/or the carbon capture gas 22 (or at least a portion thereof), as indicated by the dashed arrows in fig. 1 and 2. Since the carbon capture gas 22, such as the exhaust gas 42, has high CO₂In an amount of, thereforeThis carbon capture gas may be used as the make-up gas 48. However, since the temperature of the carbon capture gas 22 is significantly lower than the temperature of the exhaust gas 42, the proportion of the carbon capture gas 22 is adjusted to maintain the temperature of the first gas mixture above the reforming temperature. In fig. 2, the reaction section 33 is shown adjacent to the mixing section 32, but the reaction section and the mixing section need not be two distinct, distinguishable sections, since the reforming process begins when the fuel gas is mixed with the exhaust gas.

The dry reforming process occurs according to the following reaction: CO 2₂+CH₄→2H₂+2 CO. The dry reforming process may be supported by increased pressure within mixing section 32 and/or reaction section 33. To some extent, wet reforming may also occur according to the following reaction: h₂O+CH₄→3H₂+ CO. After undergoing a dry reforming process (and/or a wet reforming process), the exhaust gas 42 and the fuel gas 43 and, if appropriate, the make-up gas 48 are converted primarily into a synthesis gas 45 comprising CO and H₂. Although the reforming process is an endothermic reaction that reduces the temperature of the synthesis gas 45 relative to the temperature of the gas mixture, the post-reforming temperature of the synthesis gas 45 may still be above 1200 ℃. Since the synthesis gas 45 is intended for injection into the blast furnace 10 at the stack level 10.2, the post-reforming temperature does not coincide with the temperature distribution within the blast furnace 10. Thus, comprising CO and H₂Is introduced into the blast furnace 10 together with the synthesis gas 45. The additive gas 46 has a temperature that is significantly lower than the post-reforming temperature, for example, the additive gas may have an ambient temperature. Preferably, the synthesis gas 45 and the additive gas 46 are mixed before they are introduced into the blast furnace 10, so that the resulting second gas mixture 47 has a temperature lower than the post-reforming temperature. In particular, the ratio of the two gases may be adjusted so that the mixture 47 has a temperature corresponding to the temperature inside the blast furnace at the level of the shaft 10.2.

The introduction of synthesis gas 45 and additive gas 46 at the shaft level 10.2 helps to prevent the top gas temperature of the blast furnace 10 from falling below a certain level, even if the gas flow through the blast furnace 10 is reduced. Reducing the gas flow is beneficial because it reduces the likelihood of irregularities such as spillage or drooling and slippage.

Alternatively or additionally to the introduction of the synthesis gas 45 into the blast furnace 10 at the shaft level 10.2, the synthesis gas may be introduced at the tuyere level 10.1, as indicated by the dashed arrow in fig. 1. In this case, the temperature after reforming coincides with the temperature in the blast furnace 10 at the tuyere height 10.1. Thus, there is no need to mix the synthesis gas 45 with any added gas 46, i.e. the synthesis gas 45 may be fed as such into the blast furnace 10.

Reference symbol legend:

1 blast furnace equipment 27 hot blast

10 blast furnace 30 synthetic gas reactor

10.1 tuyere level 31 burner

10.2 shaft level 32 mixing section

12 coke 33 reaction section

13 ore 40 oxygen-enriched gas

14 blast furnace gas 41 carbonaceous material

15 stock bin 42 waste gas

20 gas purification facility 43 fuel gas

21 carbon capture device 44 first gas mixture

22 carbon capture gas 45 synthesis gas

25 furnace facility 46 addition gas

26 powdered coal 47 second gas mixture

48 make-up gas