CN203002174U - Plant for removing CO2 from the exhaust gas of a pig iron manufacturing plant - Google Patents

Abstract

The utility model discloses a device for removing CO2 from exhaust gases from pig iron manufacturing equipment, comprising a device for removing CO2 by chemisorption, wherein a component for regenerating an adsorbent: is connected to a steam turbine for utilizing waste heat from pig iron manufacture and is selectively and additionally connected to a steam turbine of a steam power plant, to enable low pressure steam from the steam turbine to be at least partially introduced into the component for regenerating the adsorbent; and/or is connected to a waste heat boiler for utilizing waste heat from pig iron manufacture and is selectively and additionally connected to a waste heat boiler of a steam power plant, to enable low pressure steam to be at least partially used for regenerating the adsorbent; and further comprises at least one pipe selected from a following pipe set: a pipe, through which top gases from a blast furnace can be introduced into the device for removing CO2 by chemisorption; and a pipe, through which exhaust gases from fusing reduction equipment is introduced into the device for removing CO2 by chemisorption.

Description

Plant for removing CO2 from the exhaust gas of a pig iron manufacturing plant

technical field

For the manufacture of pig iron, including pig iron-like products, there are essentially two known and commonly used methods: the blast furnace method and smelting reduction. the

Background technique

In the blast furnace process pig iron is first produced from iron ore by means of coke. In addition, steel scrap can be used. Steel is then made from pig iron by other methods. Iron ore in the form of ore blocks, pellets or agglomerates is mixed with reducing agents (mostly coke or coal, e.g. in the form of fine coal injection equipment) and other components (limestone, slag formation, etc.) to form a so-called charge and then Charge into blast furnace. Blast furnaces are metallurgical reactors in which a charge column is reacted convectively with hot air, the so-called hot blast. The heat required for the reaction and CO or _H2 is produced by burning the coal in the coke, which is the main part of the reducing gas and which flows through the charge column and reduces the iron ore. Pig iron and slag are produced as a result, which are discharged periodically.

In so-called oxygen blast furnaces, which are also referred to as blast furnaces with top gas or furnace gas recirculation, an oxygen-containing gas with an oxygen content (O ₂ ) of more than 90% is injected into the blast furnace during the gasification of coke or coal.

A gas cleaner (eg dust separator and/or cyclone separator in combination with wet scrubber, bag filter unit or hot gas filter) must be provided for the exhaust gas from the blast furnace, the so-called top gas or furnace gas. the

In addition, in oxygen blast furnaces a compressor, preferably an aftercooler, and a device for removing CO ₂ are usually provided for the top gas fed back into the blast furnace, and according to the prior art pressure swing adsorption is usually used.

Other options for the blast furnace process configuration are heaters for heating the reducing gases and/or combustion chambers for oxygen partial combustion. the

The disadvantages of blast furnaces are the requirements on the materials used and the high emissions of carbon dioxide. The iron carriers and coke used must be agglomerated and hard, so that sufficient cavities remain in the charge column, which ensure the throughflow of the blown air. _CO2 emissions are a drastic environmental load. Therefore, efforts are being made to replace the blast furnace process. Mention here is made of sponge iron based on natural gas (MIDREX, HYL, FINMET) and smelting reduction processes (Corex and Finex processes).

In smelting reduction a melter-gasifier is used, in which hot liquid metal is produced, and at least one reduction reactor, in which the iron ore carrier (ore lumps, fine ore, pellets, agglomerates) is reduced by means of a reducing gas, where Reducing gases are produced by gasification of coal (and if necessary a small amount of coke) with oxygen (90% or more) in a melter-gasifier. the

In the smelting reduction process usually also has

- gas cleaning equipment (on the one hand for the top gas from the reduction reactor and on the other hand for the reducing gas from the melter-gasifier),

- a compressor, preferably with an aftercooler, for the reduction gas returned to the reduction reactor,

- devices for removing CO ₂ , mostly using pressure swing-adsorption according to the prior art,

- and optionally a heater for the reducing gas and/or a combustion chamber for the partial combustion of oxygen.

The Corex process is a two-stage melting reduction process (English: smelting reduction). Smelting reduction combines a direct reduction process (pre-reduction of iron to sponge iron) with a smelting process (main reduction). the

The likewise known Finex process essentially corresponds to the Corex process, but the iron ore is added as fine ore. the

If CO ₂ emissions to the atmosphere are to be reduced during the production of pig iron, CO ₂ must be separated from the off-gas of pig iron production and stored in combined form (English: CO ₂ Capture and sequestration (CCS)).

In order to separate CO _{2 ,} pressure alternating-adsorption (English: PSA-Pressure Swing Adsorption), especially vacuum-pressure alternating-adsorption (English: VPSA-Vacuum Pressure Swing Adsorption) is currently mainly used. Pressure swing-adsorption is a physical method of selectively decomposing gas mixtures under pressure. Use dedicated porous materials (such as zeolite, activated carbon, activated silica (SiO ₂ ), activated alumina (Al ₂ O ₃ ) or combinations of these materials) as molecular sieves for the corresponding molecular adsorption and/or The diameter of the adsorbed molecule or its motion. Make full use of it in PSA, so that the gas is adsorbed on the surface to varying degrees. The gas mixture is introduced into the column column at a precisely defined pressure. The undesired components (here CO ₂ and H ₂ O) are now adsorbed and the raw materials of value (here CO, H ₂ , CH ₄ ) flow unhindered through the column train. Once the sorbent is fully loaded, depressurize and flush the column. To operate a (V)PSA device requires electrical current for the prior compression of the _CO2- enriched return gas.

The product gas stream containing valuable raw material after pressure swing adsorption also contains about 2-6% by volume of CO ₂ in the waste gas from the production of pig iron. However, the remaining gas stream from the (V)PSA plant still contains relatively high reducing gas components (eg CO, _H2 ), which are losses for the production of pig iron.

The remaining gas stream containing undesired components after pressure swing-adsorption in waste gases from pig iron production generally has the following composition:

Compound Volume % in VPSA Volume % in PSA

H ₂ 2.2 5.5

N ₂ 1.5 2.4

CO 10.9 16.8

CO ₂ 82.1 72.2

_CH4 0.7 0.9

H ₂ O 2.6 2.2 .

The remaining gas cannot simply be utilized thermally, since other fuels have to be added due to the low and/or varying calorific value of about ±50%. The calorific value of the export gas from the production of pig iron (=that part of the top gas extracted from the process of producing pig iron) is also reduced, if it is mixed into the top gas of a blast furnace or a smelting reduction plant, as a result due to high High gas compression and low gas turbine efficiency also reduce the efficiency of power plants supplied with export gas, such as combined cycle power plants (English: combined cycle power plant, CCPP for short). The flame temperature during combustion is also reduced in steam power plants or heating boilers. the

If the _CO2 from the residual gas is to be combined, the residual gas must be compressed, whereby the _CO2 is present in liquid form, and then the liquid _CO2 must be added to the storage site, for which the pressure is generally increased so much that CO ₂ is in the liquid-solid or supercritical state, where the density of CO ₂ is about 1000 kg/m ³ .

The supercritical state is the state above the critical point in the phase diagram (see Figure 1), which is characterized by a density equilibrium between the liquid and gas phases. At this point there is no distinction between the two states of matter. the

For such high compressions high power multistage compressors must be used for bringing typical densities to pipeline level, which is approximately in the range of greater than 0°C and greater than 70 bar (7,000,000Pa), preferably at ambient temperature When 80-150bar. the

But the remaining gas from (V)PSA is not suitable for combination because it has relatively high content of CO, _H2 , _N2 , _CH4 , etc. in addition to _CO2 . On the one hand, the CO content is a safety hazard, since CO leakage can cause danger to personnel (CO poisoning) and can lead to fire or explosion. In addition, the "dirt" of CO, H ₂ ... CO ₂ is a loss for the reduction work, and affects the physical properties of the compressed gas. For the compressed gas, due to the fluctuation of the content of CO, H ₂ , etc., the measurement, compression, Water solubility and transportability also vary.

Due to the contamination, the distances between stations at which the gas mixture transported or the liquid transported must be recompressed, thereby increasing investment and operating costs and their energy requirements due to additional compressors or pumps. Or the inlet pressure in the pipeline must be increased for reducing the number or power of additional pumps and compressors along the pipeline. Tests on the effect of fouling on the transport of liquefied gases have been carried out by the University of Newcastle and are disclosed in http://www.geos.ed.ac.uk/ccs/UKCCSC/Newcastle 2 07.ppt and shown in Figure 2 . the

Utility model content

It is therefore the object of the invention to separate CO ₂ from the waste gases from the production of pig iron in a greater amount than in the case of (V)PSA from other gases, but for this purpose additionally use a lower amount than in the case of (V)PSA Value energy carrier.

For this reason, the utility model proposes a device for removing _CO2 from the waste gas of pig iron manufacturing equipment, which is characterized in that it is equipped with a device for removing _CO2 by chemical adsorption, wherein the equipment parts for regenerating the adsorbent

- connected to a steam turbine (30) for utilizing waste heat from pig iron production and optionally additionally to a steam turbine (34) of a steam power plant (32) for utilizing waste heat from pig iron production The low-pressure steam of the steam turbine (30) of the steam power plant (34) and the steam turbine (34) of the steam power plant can be led at least partially into the plant components for regeneration of the adsorbent,

- and/or be connected to a waste heat boiler for utilizing waste heat from pig iron production and optionally additionally to a waste heat boiler of a steam power plant, so that low-pressure steam can be used at least partially to regenerate the sorbent,

And be provided with at least one pipeline selected from the following pipeline group

- pipelines, through which the top gas from a blast furnace, in particular from an oxygen blast furnace with top gas recirculation, can be conducted into a plant for removing _CO by chemisorption,

- Pipelines through which the exhaust gas from the smelting reduction plant can be directed to the plant for removing CO ₂ using chemisorption. The object of the present invention is achieved by a method for removing CO ₂ by chemisorption, wherein the heat used to regenerate the adsorbent is at least partly

- or supplied with low-pressure steam from steam turbines of steam power plants and/or from steam turbines used to utilize waste heat from pig iron production (reduction gas, top gas, etc.)

- and/or provide use by low-pressure steam from waste heat boilers of steam power plants and/or from waste heat boilers utilizing waste heat from pig iron production.

"Low pressure steam" refers to water vapour, which is saturated and has a pressure of 2 to 10 bar _g .

The term "steam power plant" refers on the one hand to a conventional steam power plant in which fuel is burned to generate thermal energy, from which water vapor is produced, which is utilized in a steam turbine, ie finally converted into electrical energy. the

On the other hand, it also refers to a combined power plant, to be precise, a gas and steam combined cycle power plant (English: combined cycle power plant, CCPP for short), in which the principles of a gas turbine power plant and a steam turbine power plant are combined . Here, the gas turbine serves as the heat source for the downstream waste heat boiler, which in turn serves as the steam generator for the steam turbine. the

By using a chemisorption process it is possible to increase the proportion of gaseous CO, _H2 , _CH4 recovered from pig iron production and significantly (up to several ppmv) reduce the C oxygen content in the product gas compared to (V)PSA.

Using low-pressure steam from an already existing steam process is more cost-effective than generating steam through a separate facility just for desorption. Furthermore, the use of low-value energy carriers such as steam is preferred over high-value energy carriers such as electric current from an economic and ecological point of view. Furthermore, it is more flexible to take steam from an operating steam power plant than from a steam generator operating solely for _CO2 removal, better utilizing the fuel used to generate steam in a continuously operating steam process.

The remaining gas stream after chemisorption mainly contains _CO2 and after removal of _H2S only traces of _H2S remain and can therefore be vented directly to the atmosphere and/or even sent to a _CO2 compressor followed by _CO2 storage (English: sequestration, e.g. EOR-enhanced oil recovery, EGR-enhanced gas recovery) and/or also used as a substitute for N ₂ in iron making: the remaining gas stream mainly consists of CO ₂ and can therefore be used for feeding devices, gas barrier seals and optional scrubbing gas and cooling gas consumers.

Energy consumption for compressing the residual gas stream from chemisorption up to the liquid-solid or supercritical state (>73.3 bar) is about 20-30% lower than residual gas from (V)PSA due to the low fouling content . The distances between the stations at which the gas has to be recompressed are therefore also increased in the gas line. This reduces not only the acquisition costs but also the operating costs of the CO ₂ storage.

Compared to pressure swing adsorption, chemisorption works with a lower pressure of the gas to be purified and with a lower pressure drop when removing CO ₂ , thereby also saving energy here. Unlike VPSAs, there is also no need for vacuum compressors, which likewise consume a lot of energy and entail high maintenance costs. Minimal energy consumption is especially advantageous for those countries where energy is scarce and/or expensive.

Due to the higher content of combustible raw materials in the pig iron production exhaust gases purified according to the invention, it is possible to increase the efficiency of the plant, or to reduce its specific consumption value, or to achieve a higher efficiency when burning these gases in power plants. power plant efficiency. the

The investment costs for a chemisorption process are similar to those for a VPSA plant. But the adsorption process requires a large amount of low-pressure steam, the pressure is greater than 2 bar _g , or higher such as 10 bar _g . This steam would be expensive if it had to be made separately and could not be taken from already existing steam sources.

There are different chemical adsorption processes, which are suitable for the utility model:

The first adsorption process is characterized by the use of potassium carbonate as adsorbent. Use hot potassium carbonate (English: hot potassium carbonate (HPC) or "Hot Pot"). Depending on the provider of the process, different raw materials are added to the potassium carbonate: activators (they improve CO ₂ separation) and inhibitors (they reduce corrosion). A broader process of this type is known under the name Benfield process and is offered by UOP. About 0.75 kg of steam is required per Nm ³ of gas to be purified in the Benfield process.

A second adsorption process is known from amine scrubbing with several sub-processes. In this first step, low-basic aqueous amine solutions (mostly ethanolamine derivatives) are used which reversibly chemisorb acid gases, ie for example CO ₂ . In a second process step, the acid gas is again separated thermally (by heating) from the amine and the recovered amine is reused for amine washing.

A known process for this is UOP's Amine Guard FS process, which reduces the C oxygen content to 50 ppmv and the _H2S content to 1 ppmv. The steam requirement for this process is about 1.05 kg steam per Nm ³ of gas to be purified.

Amines, such as diethanolamine (DEA), are also used as active agents in adsorption processes using potassium carbonate, for example in the Benfield process. the

For amine washes primary amines such as methylamine, ethanolamine (MEA) and/or diglycolamine (DGA) can be used. the

For amine washes, secondary amines such as diethanolamine (DEA) and/or diisopropanolamine (DIPA) can be used in addition to or instead of primary amines. the

In addition to or instead of primary and/or secondary amines it is also possible to use tertiary amines, such as triethanolamine (TEA) and/or methyldiethanolamine (MDEA). An existing process for this is BASF's aMDEA process (supplied by Linde and Lurgi), which uses reactive methyldiethanolamine (MDEA). The steam requirement for this process is about 0.85 kg steam per ^Nm3 of gas to be purified.

The method according to the invention can advantageously be used to clean the top gas from blast furnaces, in particular from oxygen blast furnaces with top gas recirculation, which are mainly operated with oxygen instead of hot air, with CO ₂ .

The method according to the invention preferably uses at least one of the following exhaust gases for the _CO purification of the exhaust gases from the smelter-reduction plant:

- off-gas from the melter-gasifier (so-called excess gas),

- exhaust gas from at least one reduction reactor,

- Exhaust gas from at least one solid bed reactor for preheating and/or reducing iron oxides and/or iron nuggets (so-called top gas).

In order to use the reducing component of the CO2 _- free gas better for pig iron production, provision can be made to use at least a portion of the cleaned offgas as reducing gas for pig iron production.

In order to obtain low-pressure steam conveniently, it is preferable to take out the low-pressure steam at the expanded end of the steam turbine or the waste heat boiler of the steam turbine. the

In the device corresponding to the method according to the invention, there is a device for removing _CO by chemisorption, wherein the device parts for regenerating the adsorbent

- or be connected to a steam turbine of a steam power plant or a steam turbine for utilizing waste heat from pig iron production, so that the low-pressure steam from the steam turbine can be conducted at least partially into plant components for regeneration of the adsorbent,

- and/or be connected to a waste heat boiler of a steam power plant and/or a waste heat boiler utilizing waste heat from pig iron production, so that at least part of the waste heat used to generate low-pressure steam can be used to regenerate the sorbent.

In particular for the blast furnace process a line can be provided via which the top gas from the blast furnace, in particular from an oxygen blast furnace with top gas recirculation, can be conducted to the plant for removing CO ₂ by chemisorption.

In the case of the smelting reduction process, correspondingly at least one conduit is provided, through which the exhaust gas from the smelting reduction plant can be conducted to the plant for removing CO ₂ by chemisorption.

At least one such conduit is connected to at least one of the following:

- with melter vaporizer,

- with one or more reduction reactors,

- With fixed bed reactor for preheating and/or reducing iron oxides and/or iron lumps.

According to a further embodiment, a duct is provided through which at least a portion of the cleaned exhaust gas can be returned to the pig iron production as reducing gas. the

In order to feed low-pressure steam into the plant for removing CO ₂ , provision can be made to connect this plant to the low-pressure part of the steam turbine and/or to the waste heat boiler.

Description of drawings

The utility model is explained in detail below with the aid of the accompanying drawings which are simplified. In the attached picture:

Figure 1 shows the phase diagram of _CO2 ,

Figure 2 shows the relationship between gas contamination and the compression stations required for this when transporting liquefied gases,

Figure 3 shows the connection between a blast furnace and two power plants according to the invention,

FIG. 4 shows the connection according to the invention between a plant for smelting reduction and two power plants.

Detailed ways

The phase diagram of _CO2 is shown in Figure 1. Plot the temperature K on the horizontal axis and the pressure bar (1 bar = 10 ⁵ P) on the vertical axis. Individual aggregate states (solid or solid state, liquid or liquid state and gas or gaseous state) are separated from each other by lines. The triple point is the point where the solid, liquid and gaseous phases meet. A supercritical state (supercritical fluid) is a state above the critical point in the phase diagram, which is characterized by an equilibrium of liquid and gas phase densities. At this point there is no distinction between the two aggregate states.

FIG. 2 shows the relationship between gas contamination and the compression stations required for this when transporting liquefied gases. Contamination is plotted in gas volume % on the horizontal axis and distance between compression stations in km on the vertical axis. The appropriate curve is marked for each soil. At 10% fouling (the right edge of the graph) H ₂ S has the least effect on the distance to the compression station, followed by SO ₂ , CH ₄ , Ar, O ₂ , N ₂ and CO, followed by NO ₂ and H ₂ maximum, where the curve nearly approaches zero.

FIG. 3 shows an oxygen blast furnace with top gas return 1 , into which iron ore from a sintering plant 2 and coke (not shown) are conveyed. Oxygen-containing gas 3 with an oxygen content >80% is fed into ring duct 4 and reducing gas 5 , also heated in reducing gas furnace 6 , is fed into blast furnace 1 together with cold or preheated O ₂ . Slag 7 and pig iron 8 are taken out below. Top or furnace gas 9 is taken off at the top of the blast furnace 1 and pre-cleaned in a dust separator or cyclone 10 and cleaned again in a wet scrubber 11 (or bag filter or hot gas filter system). The thus cleaned top or furnace gas can be taken directly from the blast furnace system as export gas 12 on the one hand and fed to an export gas container 13, and on the other hand it can be fed to a plant 14 for chemisorption of CO ₂ , in which the purified The top gas or furnace gas is previously compressed to about 2-6 bar in compressor 15 and cooled to about 30-60° C. in aftercooler 16 .

The plant 14 for chemical adsorption of CO ₂ mainly consists of an adsorber 17 and a separation device 18 . Such devices are known from the prior art and are therefore only briefly described here. The top gas or furnace gas 9 to be purified is fed from below into the adsorber 17 , while a solution of the acidic components of the adsorbed gas, for example an amine solution, flows downward from above. Here, CO ₂ is removed from the top or furnace gas and the cleaned gas is fed back into the blast furnace 1 . The loaded adsorbent (adsorbed liquid) is led from above to the separation device 18, where the adsorbent is heated to >100°C, especially 110- 120° C., whereby acid gases, especially CO _{2 ,} are released again as residual gas 20 . The remaining gas 20 can either be vented to the atmosphere after _H2S purification 21, and/or sent to another compressor 22 for _CO2 liquefaction, for onward delivery and for example underground storage or as an alternative to _N2 in the production process. Use when iron. Condensate 23 condensed in the separating device is withdrawn and can be fed to the steam circuit of the steam power plant 32 .

The export gas from the optional export gas container 13 can be conducted as fuel to the combined power plant 24 , if necessary through a buffer store 25 and a filter 26 . The output gas is sent to a gas compressor 27 and a gas turbine 28 . The waste heat of the gas turbine is utilized in the waste heat boiler 29 for the steam cycle with the steam turbine 30 . Low-pressure steam can also be withdrawn from this steam turbine 30 for the separation device 18 (not shown). the

Alternatively or additionally, the combination power plant 24 can also feed the export gas 12 as fuel (possibly via a further export gas container 31 ) to the steam boiler 33 of the steam power plant 32 . The low-pressure steam 19 is withdrawn from the last stage of the steam turbine 34 of the steam power plant 32 and fed to the separating device 18 . the

It is also possible to make full use of the pressure energy of the output gas 12 in the expansion turbine 35 (English: Top gas recovery turbine), which is arranged in this example between the output gas container 13 and the other output gas container 31 . the

The export gas 12 that is not used in neither the combined power plant 24 nor the steam power plant 32 can be used for other purposes, such as raw material drying (coal drying, fine coal drying or ore drying) 36 . the

FIG. 4 shows the connection according to the invention between a plant for smelting reduction and two power plants, namely a combined power plant 24 (which is constructed exactly the same as the combined power plant in FIG. 3 ) and a steam power plant 32 (also constituted the same as the steam power plant among Fig. 3). In FIG. 4 it is also possible to provide only the combination power plant 24 or only the steam power plant 32 or both the combination power plant 24 and the steam power plant 32 . the

Both power plants 24 , 32 are supplied with export gas 12 by the Finex plant, which can be stored intermediately in export gas containers 13 or 31 . The optional expansion turbine 35 is also used to utilize the energy contained in the output gas 12 . Export gas 12 that is not required for the power plant 24 , 32 can be sent to the feed dryer 36 again. the

The Finex plant has in this example four reduction reactors 37-40, which consist of fluidized bed reactors and are fed with fine ore. Fine ore and additives 41 are conveyed to an ore dryer 42 and from there first to a fourth reactor 37 , which then enters a third reactor 38 , a second reactor 39 and finally to a first reduction reactor 40 . However, instead of four fluidized bed reactors 37 - 40 it is also possible to have only three reactors. the

The reducing gas 43 is sent counter-currently with the fine ore. The reducing gas is fed on the bottom of the first reduction reactor 40 and discharged on the top thereof. The reducing gas can also be heated by oxygen O ₂ before entering the second reduction reactor 39 from below, likewise between the second reduction reactor 39 and the third reduction reactor 38 . The heat of the waste gas 44 from the reduction reactors 37-40 is fully utilized in the waste heat boiler 45 for steam generation, and the low-pressure steam 46 generated in the waste heat boiler is sent to the separation device 18 of the plant for chemical adsorption of _CO2 . The exhaust gas 44 exiting the waste heat boiler 45 is cleaned in a wet scrubber 47 and is used as export gas 12 in a downstream power plant as described above. According to the invention, a partial flow of the exhaust gas 44 is conducted to an adsorber 17 for removing CO ₂ .

Reducing gas 43 is produced in a melter-gasifier 48, in which coal in the form of lump coal 49 and pulverized coal 50 is delivered on the one hand (they are co-delivered with oxygen O ₂ ), and on the other hand in the melter-gasifier The iron ore that has been pre-reduced in the reduction reactor 37-40 and compacted in a hot state in the iron briquetting device 51 (English: HCT Hot Compacted Iron) is transported in the middle. Here, the iron ingots pass via a conveying device 52 into a storage vessel 53 , which is formed as a fixed-bed reactor, where the iron ingots are optionally preheated and reduced by coarsely purified generator gas 54 from the melter-gasifier 48 . Cold iron nuggets 63 can also be conveyed here. The melter-gasifier 48 is then charged with iron nuggets or iron oxide from above. It is likewise possible to remove low reduced iron (English: LRI=low reduced iron) from the iron briquette 51 .

The coal is gasified in the melter-gasifier 48, producing a gas mixture, which mainly consists of CO and _H2 , and is discharged as reducing gas (generator gas) 54 and partly sent as reducing gas 43 to the reduction reactors 37-40 .

The molten hot metal and slag are discharged in the melter-gasifier 48 , see arrow 56 . the

The top gas 54 discharged from the melter-gasifier 48 is first conducted to a separator 57 for separating the entrained dust and returning the dust to the melter-gasifier 48 via a dust burner. A portion of the head gas cleaned of coarse dust is further cleaned with a wet scrubber 58 and taken out of the Finex plant as excess gas 59 and, according to the invention, fed to the adsorber 17 of the plant 14 for chemical adsorption of CO ₂ . A further part of the purified generator gas 54 is likewise further purified in a wet scrubber 60 , led for cooling to a gas compressor 61 and then, after mixing with the CO ₂ -free product gas 62 withdrawn from the adsorber 17 , The generator gas 54 is then fed to the downstream of the melter gasifier 48 for cooling. Through this recirculation of the CO ₂ -free gas 62 , the reducing fraction contained therein can still be fully used for the Finex process and on the other hand can ensure the required cooling of the hot generator gas 54 from approximately 1050° C. to 700° C. 870°C.

The top gas 55 discharged from the storage plant 53 is cleaned in the wet scrubber 64 and then also sent to the adsorber 17 for CO ₂ removal, in which the iron nuggets or iron oxides are dedusted by means of the melter-gasifier 48 And the cooled generator gas 54 is heated and reduced.

On the one hand, low-pressure steam 46 from waste heat boiler 45 and/or low-pressure steam 19 from steam turbine 30 of combined power plant 24 and/or low-pressure steam from steam turbine 34 of steam power plant 32 can be fed to separation device 18 . However, due to the short distance between the waste heat boiler and the plant 14 for chemisorbing CO ₂ , it is preferable to use the waste heat from the iron-making process.

In this example, the condensate 32 of the separating device 18 is fed to the steam cycle of a steam power plant 32 . But it can also be fed to waste heat boilers or combined power plants. The remaining gas 20 after the separation device 18 can in turn be completely or partially vented to the atmosphere after the H ₂ S scrubber 21 or completely or partially conveyed to the CO ₂ store after being compressed by a compressor 22 .

List of reference signs

1 blast furnace

2 Sintering equipment

3 Oxygen-containing gases

4 ring pipes

5 hot air

6 Reducing gas furnace

7 Slag

8 pig iron

9 Top gas or furnace gas

10 Dust separator or cyclone separator

11 wet scrubber

12 output gas

13 Output gas container

14 Equipment for chemically adsorbing _CO2

15 compressors

16 after cooler

17 Adsorber

18 Separation device

19 low pressure steam

20 Residual gas after separation device 18

21 H ₂ S purifier

22 Compressors for CO ₂ liquefaction

23 Condensate

24 Combined Power Plant

25 buffer memory

26 filters

27 gas compressor

28 gas turbine

29 waste heat boiler

30 steam turbine

31 Additional output gas container

32 steam power plant

33 steam boiler

34 Steam turbines in steam power plants 32

35 expansion turbine

36 for raw material drying (coal drying, fine coal drying or ore drying)

37 The fourth reduction reactor

38 The third reduction reactor

39 Second reduction reactor

40 first reduction reactor

41 Fine ores and additives

42 Ore Dryer

43 Reducing gas

44 Exhaust gases from reduction reactors 37-40

45 waste heat boiler

46 Low pressure steam from waste heat boiler 45

47 Wet scrubber for exhaust gas 44

48 Melter gasifier

49 lumps of coal

50 powdered coal

51 Iron Briquetting Machine

52 conveying equipment

53 Storage vessel consisting of a solid bed reactor for preheating and reducing iron oxides and/or lumps of iron

54 Head gas or power plant gas from melter gasifier 48

55 Head gas from wet scrubber 64

56 Hot metal and slag

57 fine ore separator

58 wet scrubber

59 excess gas

60 wet scrubber

61 Gas compressor

62 _CO2 -free gas (product gas) from adsorber 17

63 cold iron block

64 Wet scrubber.

Claims (6)

1. Apparatus for removing _CO2 from the exhaust gas of a pig iron manufacturing plant, characterized in that it is provided with an apparatus for removing _CO2 by chemical adsorption, wherein the apparatus parts for regenerating the adsorbent - connected to a steam turbine (30) for utilizing waste heat from pig iron production and optionally additionally to a steam turbine (34) of a steam power plant (32) for utilizing waste heat from pig iron production The low-pressure steam of the steam turbine (30) of the steam power plant (34) and the steam turbine (34) of the steam power plant can be led at least partially into the plant components for regeneration of the adsorbent, - and/or be connected to a waste heat boiler for utilizing waste heat from pig iron production and optionally additionally to a waste heat boiler of a steam power plant, so that low-pressure steam can be used at least partially to regenerate the sorbent, And be provided with at least one pipeline selected from the following pipeline group - pipelines, through which the top gas from the blast furnace can be conducted to the plant for removing CO ₂ by chemisorption, - Pipelines through which the exhaust gas from the smelting reduction plant can be directed to the plant for removing CO ₂ using chemisorption. 2. The device of claim 1, wherein at least one such conduit is connected to at least one of the following: - with melter-gasifier (48), - with one or more reduction reactors (37-40), - with a fixed bed reactor (53) for preheating and/or reducing iron oxides and/or iron lumps. 3. The device as claimed in claim 1, characterized in that a conduit is provided through which at least a portion of the cleaned exhaust gas can be returned to the pig iron production as reducing gas. 4. A plant as claimed in any one of claims 1 to 2, characterized in that, in order to feed low-pressure steam into the plant for removal of CO ₂ , this plant is permeated with steam for the utilization of waste heat from pig iron production Flat (30) and low pressure part of the steam turbine (34) of the steam power plant and/or connected to the waste heat boiler. 5. The plant according to any one of claims 1 to 2, characterized in that the plant (14) for removing _CO2 by chemisorption is combined with a plant for pig iron manufacture and/or with a plant for processing and storing CO ₂ so that the captured CO ₂ -enriched gas can be used as a replacement gas in the iron-making process and/or for the treatment and storage of CO ₂ . 6. The device according to claim 1, characterized in that the blast furnace is an oxygen blast furnace with top gas return.

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