AT508770B1 - METHOD FOR REMOVING CO2 FROM EXHAUST GASES FROM PLANTS FOR THE PRODUCTION OF REFRIGERATED IRON - Google Patents

Abstract

A method of removing CO2 from exhaust gases from pig iron production plants is disclosed wherein the CO2 is removed by chemical absorption (14), the heat being provided for regeneration of the absorbent at least partially by either low pressure steam (19) a steam turbine (30, 34) of a steam power plant (24, 32) and / or a steam turbine is used to use the waste heat from the pig iron production, - and / or by low-pressure steam from a waste heat boiler of a steam power plant and / or from a waste heat boiler for using the waste heat from the pig iron production. As a result, the CO2 can be separated from the exhaust gases of pig iron production to a greater extent than with pressure swing adsorption of other gases and it can also be used for a lower energy source.

Description

Austrian Patent Office AT 508 770 B1 2011-04-15

description

METHOD FOR REMOVING CO 2 FROM EXHAUST GASES FROM PLANTS FOR THE PRODUCTION OF REFRIGERATED IRON

For the production of pig iron, which should also include the production of pig iron-like products, there are essentially two known common processes: the blast furnace process and the smelting reduction.

In the blast furnace method, pig iron is first produced from iron ore with the aid of coke. In addition, scrap can also be used. Thereafter, steel is produced by further processes from pig iron. The iron ore is mixed as a lump, pellets or sinter together with the reducing agents (usually coke, or coal, for example in the form of a fine coal plant) and other ingredients (limestone, slag, etc.) to the so-called Möller and then charged into the blast furnace , The blast furnace is a metallurgical reactor in which the Möllersäule reacts in countercurrent with hot air, the so-called hot blast. By burning the carbon from the coke, the necessary heat for the reaction and carbon monoxide or hydrogen, which is a significant part of the reducing gas and flows through the Möllersäule and reduces the iron ore. The result is pig iron and slag, which are tapped periodically.

In the so-called oxygen blast furnace, which is also referred to as a blast furnace with top or top gas recirculation is injected in the gasification of coke or coal oxygen-containing gas with more than 90% oxygen content (02) in the blast furnace.

For the gas leaving the blast furnace, the so-called top or top gas, gas purification must be provided (e.g., dust collectors and / or cyclones in combination with wet scrubbers, bag filter units or hot gas filters).

Furthermore, the oxygen blast furnace usually a compressor, preferably provided with aftercooler, provided for the top gas returned to the blast furnace and a device for CO 2 removal, according to the prior art usually by means of pressure swing adsorption.

Further options for the design of a blast furnace process are a heater for the reducing gas and / or a combustion chamber for partial combustion with oxygen.

The disadvantages of the blast furnace are the demands on the feedstock and the high emissions of carbon dioxide. The iron carrier used and the coke must be lumpy and hard, so that sufficient cavities remain in the Möllersäule, which ensure the flow through the blown wind. C02 emissions represent a heavy environmental impact. Therefore, there are efforts to replace the blast furnace route. These include iron sponge production based on natural gas (MIDREX, HYL, FINMET) and smelting reduction processes (Corex and Finex processes).

In the smelting reduction, a melter gasifier is used, in which hot liquid metal is produced, and at least one reduction reactor, in which the carrier of the iron ore (lump, fine ore, pellets, sinter) is reduced with reducing gas, the reducing gas in the melter gasifier by gasification of coal (and possibly a small proportion of coke) with oxygen (90% or more) is produced.

Also in the smelting reduction process are usually [0010] - gas purification systems (on the one hand for the top gas from the reduction reactor, on the other hand for the reducing gas from the melter gasifier), - a compressor, preferably with aftercooler, for in the reduction reactor to recycled reducing gas, a device for CO 2 removal, according to the prior art usually means

Pressure swing adsorption 1/16 > Austrian Patent Office AT 508 770 B1 2011-04-15 [0013] - and optionally a heater for the reducing gas and / or a combustion chamber for the partial combustion with oxygen provided.

The Corex process is a two-stage smelting reduction process. The smelting reduction combines the process of direct reduction (prereduction of iron into sponge iron) with a melting process (main reduction).

The well-known Finex method essentially corresponds to the Corex method, but iron ore is introduced as fine ore.

If the CO 2 emission into the atmosphere in the production of pig iron is to be reduced, this must be separated from the exhaust gases from the pig iron production and stored in bound form (English: C02 Capture and Sequestration (CCS)).

For the deposition of CO 2 so far mainly the pressure swing adsorption (English: PSA - Pressure Swing Adsorption), in particular the vacuum pressure swing adsorption (English: VPSA - Vacuum Pressure Swing Adsorption) is used. Pressure swing adsorption is a physical process for the selective decomposition of gas mixtures under pressure. Specific porous materials (e.g., zeolites, activated carbon, activated silica (SiO 2), activated alumina (Al 2 O 3), or the combined use of these materials) are used as a molecular sieve to adsorb molecules according to their adsorption and / or kinetic diameters. The PSA exploits the fact that gases adsorb to surfaces to different extents. The gas mixture is introduced into a column under a precisely defined pressure. Now adsorb the unwanted components (here C02 and H20) and the recyclable material (here CO, H2, CH4) flows freely through the column. Once the adsorbent is fully loaded, the pressure is released and the column rinsed. To operate a (V) PSA plant, electrical power is needed for the prior compression of the CO 2 rich recycle gas.

The product gas stream after the pressure swing adsorption, which contains the recyclables, still contains about 2-6 vol% CO 2 in exhaust gases from the pig iron production. However, the residual gas stream from the (V) PSA plant still contains relatively high reducing gas constituents (such as CO, H2), which are lost for pig iron production.

The residual gas stream after the pressure swing adsorption, which contains the undesirable components, is composed in exhaust gases from the pig iron production typically as follows:

Compound vol% at VPSA vol% at PSA H2 n2 CO C02 CH4 h2o 5.5 2.4 16.8 72.2 0.9 2.2 2.2 1.5 10.9 82.1 0.7 2.6 [0020] The residual gas can not simply be used thermally, because - due to the low and / or fluctuating calorific value of about ± 50% - it would have to be enriched with other fuels. It would also reduce the calorific value of the export gas (= that part of the top gas that is withdrawn from the process of pig iron production) from the pig iron production, if it mixes the top gas of the blast furnace or the smelting reduction plant, which in the consequence also the efficiency of with the Export gas supplied power plant, such as a combined cycle power plant (CCPP), reduced due to the high combustion gas compression and the lower efficiency of the gas turbine. In a steam power plant or boiler, the flame temperature would be reduced during combustion. If the CO 2 is to be bound from the residual gas, the residual gas must be compressed so that the CO 2 is in liquid form, and then the liquid CO 2 must be in a reservoir to which the pressure must usually be increased so far that the CO 2 is in the liquid-solid or supercritical state, where CO 2 has a density of about 1000 kg / m 3.

The supercritical state is a state above the critical point in the phase diagram (see FIG. 1) which is characterized by the equalization of the densities of liquid and gas phases. The differences between the two states of aggregation cease to exist at this point.

To such a high compression, a multi-stage compressor with high power must be used to bring the typical densities at line level, which is approximately in the range of greater than 0 ° C and greater than 70 bar (7,000,000 Pa), preferably 80-150 bar at ambient temperatures, is located.

However, the residual gas from a (V) PSA is not suitable to be bound because, in addition to CO 2, it has a relatively high proportion of CO, H 2, N 2, CH 4, etc. On the one hand, the CO content poses a safety risk, as this can lead to a risk of injury to persons (CO poisoning) and, under certain circumstances, to inflammation or explosion. Furthermore, the "impurities" CO, H2, ... of the CO 2 are lost for the reduction work and affect the physical properties of the compressed gas, for which due to the fluctuating levels of, CO, H2, etc. the measurability, the compression, the water solubility and the transport characteristics also vary.

Due to the impurities and the distances between the stations, where the transported gas mixture or the transported liquid must be re-compressed, be reduced, so that the investment and operating costs due to additional compressors or pumps and their energy needs increase. Or, the inlet pressure in the line must be increased to reduce the number or power of the additional pumps and compressors along the line.

Studies on the influence of impurities on the transport of liquefied gases has been carried out by Newcastle University and published at http://www.geos.ed.ac.uk/ccs/UKCCSC/Newcastle 2 07.ppt and is shown in FIG 2.

It is therefore an object of the invention to separate CO 2 from exhaust gases of pig iron production to a greater extent than in (V) PSA from other gases, but in addition to use a lower energy source than in (V) PSA.

The object is achieved by a method according to claim 1, wherein the CO 2 is removed by means of chemical absorption, wherein the heat for regeneration of the absorbent is at least partially provided either by low-pressure steam, which is from a steam turbine of a steam power plant and / or a steam turbine for use of waste heat from the production of pig iron (reducing gases, top gases, etc.) is used, and / or by low-pressure steam from a waste heat boiler of a steam power plant and / or from a waste heat boiler for the use of waste heat from the pig iron production ,

By "low pressure steam" is meant steam which is saturated and has a pressure between 2 and 10 barg.

Under the term "steam power plant " fall on the one hand conventional steam power plants, where thermal energy is generated by combustion of fuels, with which steam is produced, which is utilized in a steam turbine, that is ultimately converted into electrical energy.

On the other hand, this also includes a combined cycle power plant, or more precisely a combined cycle power plant (CCPP), in which the principles of a 3/16 Austrian Patent Office AT 508 770 B1 2011-04- 15

Gas turbine power plant and a steam power plant. A gas turbine serves as a heat source for a downstream waste heat boiler, which in turn acts as a steam generator for the steam turbine.

By using a chemical absorption process, the proportions of the recovered gases for the production of pig iron CO, H2, CH4 compared to a (V) PSA can be increased and the CO2 content in the product gas significantly (up to a few ppmv) can be reduced.

The use of low-pressure steam from an existing steam process is less expensive than the production of steam with its own aggregate only for desorption. In addition, the use of a low-value energy source such as steam from an economic and environmental point of view is preferable to a high-quality energy source such as electricity. The removal of steam from a running steam power plant is also more flexible than from a specially for the C02 removal operated steam generator, the fuel for steam generation is better utilized in a continuous steam process.

The residual gas stream after the chemical absorption mainly contains CO 2 and after removal of H 2 S only more traces of H 2 S and can therefore be released directly into the atmosphere and / or just fed to a CO 2 compression followed by CO 2 storage. Sequestration, eg EOR - enhanced gas recovery) and / or as a substitute for N2 in iron production: the residual gas stream consists mainly of CO 2 and can therefore be used for charging equipment, barrier seals and selected flushing and cooling gas consumers become.

Due to the low level of impurities, the energy expenditure for the compression of the residual gas stream from the chemical absorption to the liquid-solid or supercritical state (> 73.3 bar) is about 20-30% lower than for residual gas from a ( V) PSA. Consequently, the distances between the stations increase in the gas lines, where the gas must be re-compressed. Both the acquisition costs and the operating costs for C02 storage are thereby reduced.

In comparison to the pressure swing adsorption, the chemical absorption works with lower pressures in the gas to be cleaned and a lower pressure drop in the removal of CO 2, so that energy is saved here as well. Unlike a VPSA, no vacuum compressors are needed, which also consume a lot of energy and cause high maintenance costs. The low energy consumption is an advantage especially for those countries where energy is scarce and / or expensive.

Due to the now higher proportion of combustible materials in accordance with the invention purified exhaust gas of pig iron production system performance can be increased or their specific consumption can be reduced or it can also be realized in the combustion of this gas in a power plant, a higher efficiency of the power plant.

The investment costs for a chemical absorption process are comparable to those for a VPSA plant. But the absorption process needs large amounts of low-pressure steam with a pressure of more than 2 barg or higher, e.g. 10 barg. This steam would be expensive if it had to be specially made and could not be taken from an existing steam source.

There are various chemical absorption methods suitable for this invention: A first absorption method is characterized by the use of potassium carbonate as the absorbent. Hot Potassium Carbonate is used (Hot Potassium Carbonate (HPC) or " Hot Pot "). Depending on the supplier of this process, various substances are added to the potassium carbonate: activators which are intended to increase CO 2 deposition and inhibitors which are said to reduce corrosion. A widely used method of this type is known as the Benfield method and is offered by UOP. The Benfield process requires about 0.75 kg of steam per Nm3 of gas to be cleaned. A second absorption process is known as amine scrubbing with several sub-processes. In a first step, slightly alkaline aqueous solutions of amines (mostly ethanolamine derivatives) are used which reversibly chemically absorb the acidic gases, for example the CO2. In a second process step, the acidic gas is thermally separated (by heating) from the amine and the recovered amine is used again for washing.

Known methods for this are the Amine Guard FS method of UOP, which provides a reduction of the C02 content to 50 ppmv and the H2S content to 1 ppmv. The steam requirement of this process is about 1.05 kg of steam per Nm3 of gas to be purified.

Amines, such as diethanolamine (DEA), are also used as activators for absorption processes using potassium carbonate, such as for the Benfield process.

For amine scrubbing primary amines may be used, such as methylamine, monoethanolamine (MEA) and / or diglycolamine (DGA).

For amine washing secondary or secondary amines can be used in addition to or as an alternative to primary amines, such as diethanolamine (DEA) and / or diisopropanolamine (DIPA).

In addition or as an alternative to primary and / or secondary amines, it is also possible to use tertiary amines, for example triethanolamine (TEA) and / or methyldiethanolamine (MDEA). An existing process for this purpose is the aMDEA process from BASF (offered by Linde and Lurgi), which uses activated methyldiethanolamine (MDEA). The steam requirement of this process is about 0.85 kg of steam per Nm3 of gas to be purified.

With the method according to the invention may advantageously top gas from a blast furnace, in particular from an oxygen blast furnace with top gas recirculation, which is operated mainly with oxygen instead of hot air, are cleaned of CO 2.

The method according to the invention is best applied to exhaust gas from smelting reduction plants for CO 2 purification of at least one of the following exhaust gases: - exhaust gas (so-called excess gas) from a melter gasifier, - exhaust gas from at least one reduction reactor, [0053 ] - Exhaust gas (so-called top gas) from at least one fixed bed reactor for preheating and / or reduction of iron oxides and / or iron briquettes.

In order to make better use of the reducing constituents of the gas after CO 2 removal for the production of pig iron, it can be provided that at least part of the purified exhaust gas is used again as a reducing gas for the production of pig iron.

To easily obtain low-pressure steam, this is best taken at the end of the expansion of the steam turbine or the waste heat boiler of the steam turbine.

In a device according to the invention corresponding to the method according to the invention, a system for the removal of CO 2 is provided by means of chemical absorption, wherein the plant part for the regeneration of the absorbent - either with a steam turbine of a steam power plant or a steam turbine to use the waste heat from the pig iron production is connected, that low-pressure steam from the steam turbine can be at least partially directed into the part of the plant for the regeneration of the absorbent, and / or so connected to the waste heat boiler of a steam power plant and / or the waste heat boiler for using the waste heat from the pig iron production, that the waste heat can be used, at least in part, to generate low-pressure steam for the regeneration of the absorbent.

In particular, may be provided for the blast furnace process, a line with which top gas from a blast furnace, in particular from an oxygen blast furnace with Topgas- recirculation, in the plant for the removal of C02 can be conducted by chemical absorption.

In a smelting reduction process, at least one line would then be provided in accordance with which exhaust gas from a smelting reduction plant can be conducted into the plant for the removal of CO 2 by means of chemical absorption.

At least one of these lines may be connected to at least one of the following: - with a melter gasifier, [0063] - with one or more reduction reactors, [0064] - with a fixed bed reactor for preheating and / or reducing iron oxides and / or iron briquettes.

A further embodiment is that a line is provided, with which at least a portion of the purified exhaust gas can be routed back to the pig iron production again as a reducing gas.

For introducing low-pressure steam into the system for the removal of CO 2 can be provided that it is connected to the low pressure part of the steam turbine and / or the waste heat boiler.

The invention will be explained in more detail below with reference to the exemplary and schematic figures.

Fig. 1 shows a phase diagram of CO 2.

Fig. 2 shows the relationship between impurities of gases and the here necessary for compression stations in the transport of liquefied gases.

Fig. 3 shows the connection according to the invention between a blast furnace and two

Power plants.

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

FIG. 1 shows a phase diagram of CO 2. On the horizontal axis the temperature is plotted in K, on the vertical axis the pressure in bar (1 bar = 105 Pascal). The individual states of matter (solid or solid, liquid or liquid and gas or gaseous) are separated by lines.

The triple point is the point where solid, liquid and gaseous phases meet.

The supercritical state (supercritical fluid) is a state above the critical point in the phase diagram which is characterized by the equalization of the densities of liquid and gas phases. The differences between the two states of aggregation cease to exist at this point.

In Fig. 2, the relationship between impurities of gases and the compaction stations necessary for the transport of liquefied gases is shown. On the horizontal axis the impurities in% of the gas volume are plotted, on the vertical axis the distance between the compressor stations in km. For each contamination, a separate curve is drawn. At 10% contamination (right margin of illustration), the least effect on the distance of the compressor stations in H2S, followed by S02, CH4, Ar, 02, N2 and CO is the same, then N02, the greatest influence is H2, where the curve almost goes to zero.

In Fig. 3, an oxygen blast furnace is shown with top gas recirculation 1, in which iron ore from a sinter plant 2 and coke (not shown) is supplied. Oxygen-containing gas 3 having an oxygen content > 80% is introduced into the ring line 4, as well as 6 heated reducing gas 5 is introduced into the blast furnace 1 together with cold or preheated oxygen 02 in the reduction gas furnace. Slag 7 and pig iron 8 are withdrawn below. At the top of the blast furnace 1, the top or top gas 9 is removed and pre-cleaned in a dust separator or cyclone 10 and cleaned again a wet scrubber 11 (or a bag filter or hot gas filter system). The top or top gas purified in this way can be taken directly from the blast furnace system as export gas 12 and fed to an export gas container 13; on the other hand, it can be fed to a chemical absorption unit C02, with the top or top gas purified beforehand in a compressor 15 is compressed to about 2-6 barg and cooled in an aftercooler 16 to about 30-60 ° C.

The system 14 for the chemical absorption of CO 2 consists essentially of an absorber 17 and a stripper 18. Such systems are known from the prior art and will therefore be described here only in outline. In the absorber 17, the top or top gas 9 to be cleaned is introduced from below, while from above a solution absorbing the acidic components of the gas, such as an amine solution, flows downwards. Here, the CO 2 is now removed from the top or top gas and the purified gas fed back to the blast furnace 1.

The loaded absorbent (the absorbent liquid) is passed from above into the stripper 18, where it is at> 100 ° C with warm low-pressure steam 19, which has a temperature of about 120-260 ° C, in particular 150 ° C , in particular 110-120 ° C, is heated, whereby the acidic gases, in particular the CO 2, are released again as residual gas 20. The residual gas 20 can either be released into the atmosphere again after an H2S purification 21 and / or fed to another compressor 22 for the liquefaction of CO 2, in order to be forwarded and stored underground, or as a replacement for nitrogen in the iron production to use.

The resulting in the stripper condensate 23 is withdrawn and can be fed to the steam cycle of a steam power plant 32.

The export gas from an optional export gas container 13 can be fed to a combined cycle power plant 24 as fuel, optionally via a buffer memory 25 and a filter 26. The export gas is supplied in a gas compressor 27 and the gas turbine 28. The waste heat from the gas turbine is used in the waste heat boiler 29 for a steam cycle with a steam turbine 30. Also from this steam turbine 30 low pressure steam for the stripper 18 could be removed (not shown).

Alternatively or in addition to the combined cycle power plant 24, the export gas 12 - may be supplied via a further export gas container 31 and the steam boiler 33 of a steam power plant 32 as fuel. From the last stage or stages of the steam turbine 34 of the steam power plant 32, low-pressure steam 19 is removed and fed to the stripper 18.

The pressure energy content of the export gas 12 can also be utilized in an expansion turbine 35 (top gas pressure recovery turbine), which in this example is arranged between the export gas container 13 and the further export gas container 31.

Neither the combined cycle power plant 24 nor the steam power plant 32 required export gas 12 can be used for other purposes, such as for drying raw materials (coal, fine coal or ore drying) 36.

Fig. 4 shows the connection according to the invention between a plant for Schmelzre-production and two power plants, namely a combined cycle power plant 24, which is constructed exactly the same as that in Fig. 3, and a steam power plant 32, also with the same structure as that in Fig. 3. Also in Fig. 4, either only the combined cycle power plant 24 or only the steam power plant 32 may be provided or both the combined cycle power plant 24 and the steam power plant 32nd

The two power plants 24, 32 are supplied by a Finex plant with export gas 12, which can be cached in an export gas tank 13 and 31, respectively. An optional expansion turbine 35 again serves to utilize the energy contained in the export gas 12. Not required for the power plants 24, 32 export gas 12 can be supplied to a raw material drying 36 again.

The Finex plant has in this example four reduction reactors 37-40, which are formed as fluidized bed reactors and are charged with fine ore. Fine ore and additives 41 are supplied to the ore drying 42 and from there first to the fourth reactor 37, then they get into the third 38, the second 39 and finally the first reduction reactor 40. Instead of four fluidized bed reactors 37-40 but only three may be present ,

In countercurrent to the fine ore, the reducing gas 43 is passed. It is introduced at the bottom of the first reduction reactor 40 and exits at its top. Before it enters from below into the second reduction reactor 39, it can still be heated with oxygen 02, as well as between second 39 and third 38 reduction reactor. The heat of the exhaust gas 44 from the reduction reactors 37-40 is used in a waste heat boiler 45 for generating steam, the resulting low-pressure steam 46 is supplied to the stripper 18 of the plant for chemical absorption of CO 2.

The exiting the waste heat boiler 45 exhaust 44 is cleaned in a wet scrubber 47 and used as export gas 12 as described above in downstream power plants on. A partial flow of the exhaust gas 44 is - according to the invention - the absorber 17 for C02 removal supplied.

The reducing gas 43 is prepared in a melter gasifier 48, in the one hand coal in the form of lumpy coal 4 9 and coal in powder form 50 - this together with oxygen 02 - is fed, in the other hand, in the reduction reactors 37-40 iron ore formed in the briquetting 51 in a hot state into briquettes (HCI) is added. The iron briquettes arrive via a conveyor 52 in a storage tank 53, which is designed as a fixed bed reactor, where the iron briquettes with coarse purified gas generator 54 from the melter gasifier 48 optionally preheated and reduced. Cold iron briquettes 63 can also be added here. Subsequently, the iron briquettes or oxides are charged from above into the melter gasifier 48. Low reduced iron (LRI) may also be withdrawn from iron briquetting 51.

The coal in the melter gasifier 48 is gasified, resulting in a gas mixture consisting mainly of CO and H2, and withdrawn as a reducing gas (generator gas) 54 and a partial flow as reducing gas 43 to the reduction reactors 37-40 is supplied.

The hot metal melted in the melter gasifier 48 and the slag are withdrawn, see arrow 56.

The withdrawn from the melter gasifier 48 top gas 54 is first passed into a separator 57 to deposit with discharged dust and return the dust on dust burners in the melter gasifier 48.

A portion of the purified top gas from the coarse dust is further purified by wet scrubber 58 and removed as excess gas 59 from the Finex plant and - according to the invention-the absorber 17 of the system 14 for the chemical absorption of CO 2.

Another portion of the purified generator gas 54 is also further purified in a wet scrubber 60, supplied to a gas compressor 61 for cooling and then after mixing with the removed from the absorber 17, freed from C02 product gas 62 back to the generator gas 54 after the melter gasifier 48th supplied for cooling. As a result of this recycling of the gas liberated from C02, the reducing proportions contained therein can still be utilized for the Finex process and, on the other hand, the required cooling of the hot generator gas 54 from approximately 1050 ° C. to 700-870 ° C. can be ensured.

The top gas 55 emerging from the storage facility 53, where the iron briquettes or iron oxides are heated and reduced with dedusted generator gas 54 from the melter gasifier 48, is discharged in a Wet scrubber 64 cleaned and then also supplied to the absorber 17 for the removal of CO2.

On the one hand, the stripper 18 can be supplied with low-pressure steam 46 from the waste-heat boiler 45 and / or low-pressure steam 19 from the steam turbine 30 of the combined cycle power plant 24 and / or low-pressure steam from the steam turbine 34 of the steam power plant 32. Preferably, the waste heat from the ironmaking process should be used because of the short distances between the waste heat boiler and the chemical absorption absorption facility C02.

The condensate 23 of the stripper 18 is supplied to the steam cycle of the steam power plant 32 in this example. But it can also be supplied to the waste heat boiler or the combined cycle power plant.

The residual gas 20 after the stripper 18 can again be released into the atmosphere in whole or in part after an H2S purification 21 or can be fed in whole or in part - after compression by means of the compressor 22 - to a CO 2 storage.

REFERENCE LIST 1 Blast furnace 2 Sintering plant 3 Oxygenated gas 4 Ring line 5 Hot blast 6 Reduction gas furnace 7 Slag 8 Pig iron 9 Top or top gas 10 Dust separator or cyclone 11 Wet scrubber 12 Export gas 13 Export gas tank 14 C02 chemical absorption unit 15 Compressor 16 Aftercooler 17 Absorber 18 Stripper 19 Low pressure steam 20 Residual gas after stripper 18 21 H2S cleaning 22 Compressor for liquefying CO 2 23 Condensate 24 Combined cycle power plant 25 Buffer tank 26 Filter 27 Gas compressor 28 Gas turbine 29 Waste heat boiler 30 Steam turbine 31 Additional export gas tank 32 Steam power plant 33 Steam boiler 34 Steam turbine 32 35 Expansion turbine 9/16

Claims (19)

Austrian Patent Office AT 508 770 B1 2011-04-15 36 For raw material drying (charcoal, fine coal or ore drying) 37 Fourth reduction reactor 38 Third reduction reactor 39 Second reduction reactor 40 First reduction reactor 41 Fine ore and additives 42 Earthing 43 Reduction gas 44 Exhaust gas from reduction reactors 37-40 45 Waste heat boiler 46 Low-pressure steam from waste heat boiler 45 47 Wet scrubber for waste gas 44 48 Melt carburetor 49 Charcoal 50 Coal in powder form 51 Iron briquetting 52 Conveyor 53 as a fixed bed reactor designed storage tank for preheating and reducing iron oxides and / or iron briquettes 54 Top or generator gas from melter gasifier 48 55 Topgas from wet scrubber 64 56 hot metal and slag 57 separator for fine ore 58 wet scrubber 59 excess gas 60 wet scrubber 61 gas compressor 62 gas released from C02 (product gas) from absorber 17 63 cold iron briquettes 64 wet scrubber claims 1. Verfa for removing CO 2 from exhaust gases (12, 44, 55, 59) of pig iron production plants, characterized in that the CO 2 is removed by means of chemical absorption (14), the heat for the regeneration of the absorbent being at least partially replaced by low-pressure steam (19) is made available from a steam turbine for the use of waste heat from the pig iron production and optionally additionally low-pressure steam (46) from a steam turbine (30, 34) of a steam power plant (24, 32) is used, and / or from a waste heat boiler (45 ) comes to use the waste heat from the production of pig iron and optionally additionally by low-pressure steam (46), which comes from a waste heat boiler of a steam power plant. 2. The method according to claim 1, characterized in that is used as an absorbent potassium carbonate. 3. The method according to claim 1 or 2, characterized in that it comprises an amine wash. 4. The method according to claim 3, characterized in that primary amines, such as methylamine, monoethanolamine (MEA) and / or diglycolamine (DGA) are used. 5. The method according to claim 3 or 4, characterized in that secondary amines, such as diethanolamine (DEA) and / or diisopropanolamine (DIPA) are used. 6. The method of claim 3, 4 or 5, characterized in that tertiary amines, such as triethanolamine (TEA) and / or methyldiethanolamine (MDEA) are used. 10/16 Austrian Patent Office AT 508 770 B1 2011-04-15 7. The method according to any one of claims 1 to 6, characterized in that top gas from a blast furnace, in particular from an oxygen blast furnace (1) is cleaned with Topgasrückführung of CO 2. 8. The method according to any one of claims 1 to 7, characterized in that the exhaust gas (44, 55, 59) is purified from a smelting reduction plant. 9. The method according to claim 8, characterized in that at least one of the following exhaust gases is purified: - exhaust (59) from a melter gasifier (48), - exhaust (44) from at least one reduction reactor (37-40), - exhaust (55 ) from at least one fixed bed reactor (53) for preheating and / or reducing iron oxides and / or iron briquettes. 10. The method according to any one of claims 1 to 9, characterized in that at least a portion of the CO 2 purified exhaust gas (62) is used again as a reducing gas for pig iron production. 11. The method according to any one of claims 1 to 10, characterized in that low-pressure steam at the end of the expansion of the steam turbine (30, 34) is removed. 12. The method according to any one of claims 1 to 11, characterized in that the recovered CO 2 rich gas from the CO 2 removal process is used as a substitute gas in the iron production process and / or for the preparation and storage of CO 2. 13. A device for carrying out the method according to one of claims 1 to 12, characterized in that a plant (14) is provided for the removal of CO 2 by means of chemical absorption, wherein the plant part (17) for the regeneration of the absorbent - so with a steam turbine ( 30) for using the waste heat from the pig iron production and optionally additionally connected to a steam turbine (34) of a steam power plant (32) that low-pressure steam from the steam turbine (30, 34) at least partially into the plant part (17) are passed for the regeneration of the absorbent can, - and / or so with the waste heat boiler (29) for using the waste heat from the pig iron production and optionally additionally connected to the waste heat boiler (33) of a steam power plant that the low pressure steam can be used at least partially for the regeneration of the absorbent. 14. The apparatus according to claim 13, characterized in that a line is provided, with which top gas (12) from a blast furnace, in particular from an oxygen blast furnace (1) with Topgasrückführung, passed into the system (14) for the removal of CO 2 by means of chemical absorption can be. 15. The apparatus according to claim 13, characterized in that at least one line is provided, with which exhaust gas (44, 55, 59) can be passed from a smelting reduction plant in the system (14) for the removal of CO 2 by means of chemical absorption. 16. The device according to claim 15, characterized in that at least one of these lines is connected to at least one of the following devices: - with a 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 briquettes. 17. Device according to one of claims 13 to 16, characterized in that a line is provided, with which at least a part (62) of the purified exhaust gas can be routed back to the pig iron production again as a reducing gas. 18. Device according to one of claims 13 to 17, characterized in that for introducing low-pressure steam into the system for the removal of C02, this is connected to the low pressure part of the steam turbine (30, 34) and / or to the waste heat boiler. 11/16 Austrian Patent Office AT 508 770 B1 2011-04-15 19. Device according to one of claims 13 to 18, characterized in that the plant (14) is connected to remove CO 2 by means of chemical absorption so with a plant for pig iron production and / or a plant for the preparation and storage of CO 2, that the obtained C02 rich gas can be used as a substitute gas in the iron production process and / or for the treatment and storage of C02. For this 4 sheets drawings 12/16