Method for removing acidic gases from a process gas of a co2-emitting installation, and co2-emitting installation comprising a device for gas scrubbing of process gases
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-06
- Publication Date
- 2026-08-13
Smart Images
Figure EP2026053117_13082026_PF_FP_ABST
Abstract
Description
[0001]
[0002] February 5, 2026
[0003] Method for removing acidic gases from a process gas of a CO2-emitting plant and a CCh-emitting plant, comprising a device for gas scrubbing of process gases
[0004] The invention relates to a method for removing acidic gases from a process gas of a CCh-emitting plant, as well as a CCh-emitting plant comprising a device for gas scrubbing of process gases, and the use of a process gas condensate enriched with amines and nitrogenous decomposition products of the amines, in particular ammonia, of a CCh-emitting plant for the reduction of nitrogen oxides (NOx) in a process gas of a CCh-emitting plant with selective non-catalytic reduction technology or with selective catalytic reduction technology.
[0005] Processes for removing CO2 from process gases of CCh-emitting plants using an amine-containing absorbent are employed in industry to reduce the release of the climate-damaging gas CO2 into the atmosphere. Process gases from CCh-emitting plants contain, in addition to CO2, other acidic components such as sulfur oxides (SOx) and NO. X HCl and HF must be removed from the process gas before CCh separation to prevent decomposition of the amine-containing absorbent. For this purpose, the process gas is typically conditioned before entering the so-called CCh absorber.
[0006] This conditioning process typically involves bringing the process gas into contact with water containing an alkali, such as a sodium hydroxide solution, as an additional reactant. This process primarily washes out the strongly acidic components of the process gas, such as SO2 and HCl. Furthermore, the process gas is cooled from approximately 40°C to 250°C to approximately...
[0007] The process gas is cooled to 30–45 °C. Cooling below the water dew point results in the formation of process gas condensate. This condensate, mixed with alkali, has a pH value between 6 and 8 and is typically used for water treatment or wastewater treatment.
[0008] After treatment of the CC-containing process gas with the amine-containing absorbent, the CC-depleted process gas contains basic components, such as volatile decomposition products of the amine-containing absorbent (e.g., ammonia) and amines, due to degradation of the amine-containing absorbent and droplet entrainment. Amines and ammonia can harm aquatic organisms and persist in waterways and soils. Therefore, to protect the environment, they should not be emitted. For this reason, several different purification steps of the CC-depleted process gas are typically performed downstream of the CCh separation in the CCh absorber.
[0009] These downstream cleaning steps typically include one or more water washing stages, droplet separators, or acid washing stages.
[0010] In acidic scrubbing, an acid and, if necessary, fresh water are added to the circulating scrubbing water to lower the pH value of the scrubbing water to a value between 3 and 7, thus reactively removing the basic components from the CCh-poor process gas. The discharged water from the acidic scrubbing process, laden with the decomposition products of the amine-containing absorbent as well as the amines themselves, is generally treated as wastewater or thermally disposed of.
[0011] In WO 2012 / 131016 Al, a so-called dry bed was proposed for the retention of amines during CO2 removal from CO2-containing process gases using amine-containing absorbents. A significant disadvantage of the method described in WO 2012 / 131016 Al is that, on the one hand, a high acid capacity must be achieved in the process gas condensate to reliably remove alkaline components in acidic scrubs from the CO2-depleted process gas.
[0012] RK / RK 240604WO February 5, 2026 to be able to wash out, but on the other hand it is necessary to achieve the lowest possible acid capacity of the CCh-containing process gas condensate for CCh absorption in order to minimize the breakthrough of acidic components that damage the amine-containing absorbent.
[0013] The present invention is based on the objective of providing an improved method for removing acidic gases from a process gas of a CCh-emitting plant using an amine-containing absorbent, which does not have the disadvantages of the prior art and in particular makes it possible to save the consumption of input materials such as acids, fresh water and alkalis and to significantly reduce the effort required for the disposal or treatment of waste streams.
[0014] This problem was solved by a process for removing acidic gases from a process gas of a CCh-emitting plant using an amine-containing absorbent, which is brought into contact with the process gas in an absorber column and which is regenerated in a desorber column and returned to the absorber column after cooling, characterized in that the process gas undergoes at least two-stage conditioning in a conditioning column before being brought into contact with the amine-containing absorbent, wherein in a first stage of conditioning the process gas is cooled, yielding an acidic process gas condensate, and in the second stage of conditioning a conditioned process gas is obtained, wherein
[0015] i] the acidic process gas condensate is fed completely or partially to a washing column downstream of the absorber column or to a washing stage in the absorber column, resulting in an acidic process gas condensate enriched with amines and nitrogenous decomposition products of the amines,
[0016] RK / RK 240604WO February 5, 2026 and / or
[0017] ii] the acidic process gas condensate is fed completely or partially to a washing column upstream of the conditioning column.
[0018] The problem is further solved by a CCh-emitting plant comprising a device for gas scrubbing of process gases of the CC-emitting plant with the features of claim 12.
[0019] It was surprisingly found that the use of at least two-stage conditioning in a conditioning column advantageously allows for a minimum reduction of feedstocks, such as alkalis, since only trace amounts of acidic components, such as SO2, reach the second stage of process gas conditioning and need to be neutralized. This allows for a significant reduction in the use of alkalis for neutralizing the process gas condensate compared to prior art processes with single-stage conditioning.
[0020] By recirculating the acidic process gas condensate, as provided for in the invention, into a scrubbing column downstream of the absorber column or into a scrubbing stage within the absorber column, and / or by recirculating the acidic process gas condensate into a scrubbing column upstream of the conditioning column, the additional feedstocks fresh water and acid can be partially or even completely eliminated. Minimizing the consumption of operational feedstocks such as alkalis, acids, and fresh water is not only economically but also ecologically advantageous.
[0021] Furthermore, the process according to the invention makes it possible to reduce the wastewater from the conditioning column to a minimum necessary for trace substance removal, since part or all of the process gas condensate is used as process water in the absorber column and / or in the conditioning column.
[0022] RK / RK 240604WO 5 February 2026 upstream washing column is used and thus fresh water is substituted without causing additional wastewater flows.
[0023] The inventive method for removing acidic gases from a process gas of a CC-emitting plant provides for the use of an amine-containing absorbent which is brought into contact with the process gas in an absorber column and which is regenerated in a desorber column and fed back to the absorber column after cooling.
[0024] For the purposes of this invention, a process gas is understood to be an exhaust gas from a CCh-emitting plant, for example, flue gas. The CCh-emitting plant can be selected from residual material incineration plants, waste incineration plants, sewage sludge incineration plants, biomass incineration plants, CCh-emitting power plants, CCh-emitting petrochemical plants, CCh-emitting cement plants, or CCh-emitting steel plants, as well as other metal processing plants. In addition to CCh, the process gas can contain other components such as water vapor, solid particles like fly ash and soot, sulfur oxides such as Sch, Sch, etc. (also collectively referred to as "SO"). X “”,” nitrogen oxides, such as NO, NO2, N2O3 and N2O4 (also collectively referred to as “NO”). X“designated”), containing HCl and HF. The process gas is typically cleaned of any solid particles present by separating them in electrostatic, tubular, and / or cloth filters, resulting in a subsequent low particle count. Therefore, at the time the process gas comes into contact with the amine-containing absorbent in an absorber column, it is not only low in acidic components (each < 20 mg / mN⁻¹). 3 , with mg / mN 3 =
[0025] milligrams / standard cubic meter), but also low in solid particles, such as soot and fly ash (< 5 mg / mN 3 ).
[0026] Aqueous solutions containing 10 to 60 wt% of at least one amine are typically used as amine-containing absorbents. Preferably
[0027] RK / RK 240604WO February 5, 2026 amines such as monoethanolamine, 2-(methylamino)ethanol, 2-(ethylamino)-ethanol, 2-(n-butylamino)ethanol, 2-amino-2-methylpropanol, N-(2-aminoethyl)-piperazine, methyldiethanolamine, ethyldiethanolamine, diemthylaminopropanol, t-Butylaminoethoxyethanol, 2-aminomethylpropanol, 3-methylaminopropylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, 152,2-dimethyl-l,3-diaminopropane, hexamethylenediamine, 1,4-diaminobutane, 3,3-iminobispropylamine, tris(2-aminoethyl)amine, Bis(3-dimethylamino-propyl)amine, tetramethylhexamethylenediamine, piperazine, 2-methylpiperazine, N-Methylpiperazine, 1-Hydroxyethylpiperazine, 1,4-Bis-hydroxyethylpiperazine, 4-Hydroxyethylpiperidine, Homopiperazine, Piperidine, 2-Hydroxyethylpiperidine, Morpholine, or mixtures thereof are used. Particularly preferred amines are monoethanolamine, piperazine, 2-Amino-2-methylpropanol, methyldiethanolamine, diethanolamine, and / or 1-Hydroxyethylpiperazine.
[0028] The amine-containing absorbent binds CO2 from the process gas, among other things by binding a CC molecule to the amine group of at least one amine, forming a carbamate. Furthermore, dissolved CO2 is converted to hydrogen carbonate via an amine-catalyzed reaction.
[0029] Contacting the process gas with the amine-containing absorbent in the absorber column can be accomplished using conventional methods and devices known to those skilled in the art. Packed packings are suitable devices for this purpose. Structured packings are particularly preferred. In this configuration, CO2 is preferably absorbed from the conditioned process gas by the amine-containing absorbent in the absorber column.
[0030] Amines and nitrogen-containing decomposition products of amines pass into the CC-poor flue gas stream due to their vapor pressure or through aerosol formation. To reduce emissions of these substances, the CC-poor flue gas is fed to the scrubbing column downstream of the absorber column or to the scrubbing stage within the absorber column itself. Contact between the process gas and the amine-containing absorbent in the absorber column preferably occurs during
[0031] RK / RK 240604WO 5 February 2026 Temperatures from 35°C to 65°C, especially preferred at temperatures from 40°C to 60°C.
[0032] In the desorber column downstream of the absorber column, the amine-containing absorbent is regenerated. Preferably, the CO₂ is separated from the amine-containing absorbent in the desorber column. This can be done in a manner known to those skilled in the art. In particular, the CO₂-laden amine-containing absorbent can be preheated via a cross-flow heat exchanger and introduced into a desorber column, also called a stripper. Here, steam at approximately 110°C to 130°C flows upstream of the CCh-laden amine-containing absorbent near the bottom of the desorber column. This steam is generated in a reboiler by heating a partial stream of the CCh-laden amine-containing absorbent, for example, using low-pressure steam.
[0033] In the process according to the invention, the process gas passes through before the
[0034] In contact with the amine-containing absorbent, a conditioning process of at least two stages is carried out in a conditioning column, wherein in a first stage of conditioning the process gas is cooled, yielding an acidic process gas condensate, and in the second stage of conditioning a conditioned process gas is obtained.
[0035] According to a preferred embodiment of the process according to the invention, the process gas undergoes at least two-stage conditioning immediately before contact with the amine-containing absorbent. "Immediately before" in the context of the invention means that the process gas stream flows through the conditioning column and, after exiting the conditioning column, is introduced directly into the absorber column, where it is brought into contact with the amine-containing absorbent. In contrast, the term "before" does not preclude the process gas stream from passing through further components of the apparatus after exiting the conditioning column, such as a blower for pressure increase or devices for aerosol particle separation.
[0036] RK / RK 240604WO 5 February 2026 turbulent spray scrubber or a Brownian demister, passes before it comes into contact with the amine-containing absorbent in the absorber column.
[0037] The same applies to the use of the term "after". That is, if the term "after" has not been further defined, it is understood within the meaning of the invention to mean that the process gas flow between the aforementioned device part as the starting point and the aforementioned device part as the arrival point may pass through further device parts.
[0038] In the context of the invention, at least two-stage conditioning in a conditioning column is understood to mean that the process gas passes through a conditioning column comprising at least one first stage and at least one second stage. Furthermore, the conditioning process, and thus the conditioning column itself, may include additional stages. The at least first and at least second stages are described in more detail below. According to an alternative embodiment of the process according to the invention, the order of the stages can also be reversed, i.e., the process gas then passes through the at least second stage and then the at least first stage of the conditioning column during the conditioning process.In the first stage of the conditioning column, acidic components of the process gas are preferably concentrated in the acidic process gas condensate, and in the second stage of the conditioning column, remaining acidic components are scrubbed from the process gas using an alkaline solution. This step, preferably taking place in the second stage, in which an alkaline solution is used to neutralize the remaining acidic components, is also referred to as alkaline scrubbing. The conditioning column, which preferably has at least two stages, is preferably a packed column containing structured packings or packing materials.
[0039] In the first stage of conditioning the process according to the invention, in which the process gas is cooled, a large part of the water contained in the process gas condenses out and a large part of the acidic components of the process gas are removed.
[0040] RK / RK 240604WO February 5, 2026: Due to the high water solubility of the acidic components of the process gas, especially SO2, these components are scrubbed from the process gas. For example, the SO2 contained in the process gas forms sulfurous acid (H2SO3) when dissolved in water or sulfuric acid (H2SO4) after reacting with oxygen. It has proven particularly practical to cool the process gas in the stages of the at least two-stage conditioning process to a temperature below the water dew point, in particular to a temperature between 30 and 75°C. The cooling is dimensioned so that the resulting process gas condensate is sufficient to scrub the acidic components from the process gas to a large extent and to utilize the acidic process gas condensate in the scrubbing column downstream of the absorber column or in a scrubbing stage within the absorber column.According to a preferred embodiment of the inventive method, no alkali is added in the first stage of conditioning.
[0041] The cooling of the process gas in the first conditioning stage is achieved, for example, by using cooled circulating water, such as process gas condensate from the bottom of the first conditioning column, cooled by a heat exchanger or a heat pump. Preferably, the circulating water is trickled into the first conditioning stage, thus bringing it into contact with the process gas to cool it. In addition to the process gas condensate, further process water can be added to the first conditioning stage, in which the acidic components of the process gas also accumulate. This acidic process water can be used in other acidic scrubbing columns of the process to reduce or completely replace the amount of sulfuric acid otherwise required for acidification.
[0042] In the second stage of conditioning in the process according to the invention, a conditioned process gas is obtained. It has proven particularly practical if, in the second stage of conditioning, the remaining residue of the process condensate is obtained by further cooling. According to a preferred
[0043] RK / RK 240604WO February 5, 2026 In an embodiment of the process according to the invention, an alkali, in particular sodium hydroxide, is added in the second stage of the at least two-stage conditioning process. Preferably, just enough alkali is added to the circulating water in the second stage of the conditioning column to wash out the acidic components remaining in the process gas at a pH of 6-8. The resulting neutralized process condensate is preferably used as cooling tower makeup water. Here, too, the circulating water can be, for example, process gas condensate that originates from the bottom of the second stage of the conditioning column and has been cooled by a heat exchanger.Preferably, the circulating water is first mixed with lye and then, in the second stage of conditioning, in which lye is preferably used, trickled through and thus brought into contact with the process gas in order to condition the process gas.
[0044] According to the invention, the acidic process gas condensate is fed completely or partially to a washing column downstream of the absorber column or to a washing stage in the absorber column, resulting in an acidic process gas condensate enriched with amines and nitrogenous decomposition products of the amines.
[0045] When the following text refers to a washing stage in the absorber column, it means the use of an absorber column that includes both an absorber stage and at least one washing stage. In this case, the washing stage is an integral part of the absorber column. In contrast, a washing column downstream of the absorber column is not an integrated part of the absorber column; rather, the washing column is a separate column located downstream of the absorber column.
[0046] By using the acidic process gas condensate generated during conditioning, particularly in the first stage of conditioning, in a washing column downstream of the absorber column or a washing stage in the
[0047] RK / RK 240604WO February 5, 2026 In the absorber column, the amines and nitrogenous decomposition products of the amines are scrubbed from the CCh-poor process gas in the absorber column or in the absorber stages of the absorber column. This significantly reduces or even completely replaces the otherwise necessary amount of sulfuric acid and fresh water. Additionally, the wastewater streams typically generated from the conditioning column are also reduced.
[0048] According to a preferred embodiment, the process gas condensate enriched with amines and nitrogenous decomposition products of the amines comprises ammonia.
[0049] According to an alternative version of the invention, or in addition to the aforementioned use of the acidic process gas condensate generated in the first stage of the conditioning column in a washing column downstream of the absorber column or in a washing stage within the absorber column, the acidic process gas condensate is fed completely or partially to a washing column upstream of the conditioning column. By alternatively or additionally using the acidic process gas condensate generated, particularly in the first stage of conditioning in the conditioning column, in a washing column upstream of the conditioning column, the required amount of fresh water is significantly reduced or even completely replaced.
[0050] In CC-emitting plants where the process gas contains nitrogen oxides (NOx), when using selective non-catalytic reduction technology (SNCR), ammonia (NHs) or urea is added as a feedstock to the hot process gas at the end of the combustion chamber, or when using selective catalytic reduction technology (SCR), upstream of the solid catalyst layers for the reduction of nitrogen oxides.
[0051] According to a preferred embodiment of the inventive method, it is provided that the mixture containing amines and nitrogenous decomposition products of the
[0052] RK / RK 240604WO February 5, 2026. Process gas condensate enriched with amines, in particular ammonia, is fed into a combustion chamber of a CO2-emitting plant with selective non-catalytic reduction technology. It has proven particularly practical to feed the process gas condensate, enriched with amines and nitrogen-containing decomposition products of the amines, especially ammonia, into the combustion chamber at a temperature between 850°C and 1050°C. Surprisingly, it has been found that this embodiment of the process according to the invention can partially or completely replace the use of ammonia, ammonia water (aqueous ammonia solution), or amines for NOx reduction that is necessary in the process.
[0053] According to an alternative preferred embodiment of the process according to the invention, the process gas condensate enriched with amines and nitrogenous decomposition products of the amines, in particular ammonia, is fed upstream of a catalyst layer in a CCh-emitting plant with selective catalytic reduction technology. Preferably, the process gas condensate enriched with amines and nitrogenous decomposition products of the amines, in particular ammonia, can be fed upstream of the catalyst layer at a temperature between 170°C and 380°C. These temperatures have proven advantageous to ensure evaporation of the process gas condensate enriched with amines and nitrogenous decomposition products of the amines, in particular ammonia, and to achieve sufficient catalytic activity.Even for this embodiment of the inventive method, it has surprisingly turned out that the use of ammonia, ammonia water (aqueous ammonia solution) or amines necessary in the process for NOx reduction can be partially or completely replaced.
[0054] Furthermore, the use of caustic soda in the downstream alkaline scrubbers of the process gas cleaning system of CO2-emitting plants can also be reduced.
[0055] RK / RK 240604WO February 5, 2026, which additionally saves the operating costs for input materials in the CCh-emitting plants.
[0056] A further object of the invention is a CCh-emitting plant comprising a device for gas scrubbing of process gases of the CCh-emitting plant, wherein the device for gas scrubbing comprises at least one process gas path, a first scrubbing column, optionally further process gas scrubbing columns, a conditioning column of at least two stages downstream of the first scrubbing column or the optional further process gas scrubbing columns, a CCh separation unit with an absorber column and a desorber column, and a second scrubbing column downstream of the absorber column or an absorber column comprising an absorber stage and a scrubbing stage, characterized in that
[0057] (i) the conditioning column, which has at least two stages, is connected to the second washing column downstream of the absorber column or to the washing stage of the absorber column in such a way that an acidic process gas condensate stream from the first stage of the conditioning column, which has at least two stages, is directed wholly or partly into the second washing column downstream of the absorber column or into the washing stage of the absorber column,
[0058] and / or
[0059] (h) the conditioning column, which has at least two stages, is connected to the first washing column in such a way that a process gas condensate stream from one of the two stages of the conditioning column, which has at least two stages, is directed wholly or partly into the first washing column.
[0060] RK / RK 240604WO February 5, 2026 For the individual features of the CCh-emitting plant according to the invention, what has been said for the corresponding features of the method according to the invention applies accordingly.
[0061] According to a preferred embodiment of the invention, the CCh-emitting plant is a CCh-emitting plant with selective non-catalytic reduction technology, wherein the second washing column downstream of the absorber column or the washing stage of the absorber column is connected to a combustion chamber of the CCh-emitting plant in such a way that a process gas condensate stream enriched with amines and nitrogenous decomposition products of the amines, in particular ammonia, is directed from the second washing column downstream of the absorber column or the washing stage of the absorber column into the combustion chamber of the CCh-emitting plant.
[0062] According to an alternative preferred embodiment of the invention, the CCh-emitting plant is a CCh-emitting plant with selective catalytic reduction technology, which has at least one catalyst layer for removing nitrogen oxides (NOx) from the process gas, wherein the second scrubbing column downstream of the absorber column or the scrubbing stage of the absorber column is connected to the catalyst layer in such a way that a process gas condensate stream enriched with amines and nitrogenous decomposition products of the amines, in particular ammonia, is injected from the second scrubbing column downstream of the absorber column or the scrubbing stage of the absorber column upstream of the catalyst layer.
[0063] Finally, another object of the invention is the use of a process gas condensate from a CCh-emitting plant enriched with amines and nitrogenous decomposition products of the amines, in particular ammonia, for the reduction of NO.X in a process gas of a CCh-emitting plant with selective non-catalytic reduction technology or with selective catalytic reduction technology.
[0064] RK / RK 240604WO February 5, 2026 For the individual features of the use according to the invention, what has been said above for the corresponding features of the method according to the invention applies accordingly.
[0065] The invention will then be explained in more detail with reference to the exemplary embodiments shown in the figures.
[0066] They show:
[0067] Fig. 1 A preferred embodiment of the method according to the invention
[0068] Fig. 2 Alternative embodiments of the method according to the invention
[0069] Figure 1 shows a preferred embodiment of the inventive process for removing acidic gases from a process gas of a CC-emitting plant using an amine-containing absorbent. The process gas is generated in a combustion chamber (1) and is fed from there into a steam generator (2). The process gas then undergoes process gas cleaning (3), in particular dust removal using electrostatic precipitators and fabric filters and / or denitrification without catalysts, followed by an acid scrubbing stage (4). Via optional, further process gas scrubbing stages, in particular a neutral water scrubbing or an alkaline scrubbing stage, and the stack (5), the process gas is introduced into the first stage (6) of a conditioning column with at least two stages. In the first stage (6) of the at least two-stage conditioning process, the process gas is cooled and an acidic process gas condensate is obtained.In the second stage (7) of the conditioning process, caustic soda is preferably added, and a conditioned process gas is obtained. The acidic process gas condensate obtained in the first stage (6) of the at least two-stage conditioning process is completely fed to a scrubbing column (9) downstream of the absorber column (8) or to a scrubbing stage (9) within the absorber column (8), optionally including integrated flue gas cleaning techniques, such as, in particular, a dry bed and water scrubbing.
[0070] RK / RK 240604WO February 5, 2026: An acidic process gas condensate enriched with amines and nitrogenous decomposition products of the amines is produced. This acidic process gas condensate, enriched with amines and nitrogenous decomposition products of the amines, is fed into an acid scrubber (4) upstream of the two-stage conditioning process. In the acid scrubber (4), water enriched with ammonia is obtained and fed to the combustion chamber (1). This is advantageous if the CO2-emitting plant is a CCh-emitting plant with selective non-catalytic reduction technology, as it allows the use of ammonia, ammonia water (aqueous ammonia solution), or amines for NOx reduction, which is necessary in the process, to be partially or completely replaced.The conditioned process gas obtained in the second stage (7) of the at least two-stage conditioning process is fed into the absorber column (8), optionally incorporating comprehensively integrated flue gas cleaning technology. Process gas condensate from the second stage (7) of the at least two-stage conditioning process is advantageously used as make-up water for cooling towers or scrubbers. In the absorber column (8), optionally incorporating comprehensively integrated flue gas cleaning technology, the conditioned process gas is brought into contact with an amine-containing absorbent, which is regenerated in a desorber column (not shown in the figure) and, after cooling, is returned to the absorber column (8). The amine-containing absorbent removes CO2 from the process gas.The CCh-poor process gas is then fed to optional further flue gas treatment stages, such as a dry bed and a water scrubber, and then fed to the scrubbing column (9) downstream of the absorber column (8) or to the scrubbing stage (9) in the absorber column (8), optionally with comprehensively integrated flue gas cleaning techniques.
[0071] Figure 2 shows alternative embodiments of the inventive method for removing acidic gases from a process gas of a CC-emitting plant using an amine-containing absorbent. The process gas is generated in a combustion chamber (1) and is directed from there into a steam generator (2). Subsequently, the process gas passes through a
[0072] RK / RK 240604WO February 5, 2026 Process gas cleaning (3), such as, in particular, dust removal using electrostatic precipitators and fabric filters and / or denitrification with or without catalysts, followed by acid scrubbing (4). Via optional further process gas scrubbing (not shown), such as, in particular, neutral water scrubbing or alkaline scrubbing, the process gas reaches the stack (5) and is introduced from there into the first stage (6) of a conditioning column consisting of at least two stages. In the first stage (6) of the conditioning column consisting of at least two stages, the process gas is cooled and an acidic process gas condensate is obtained. In the first stage (6) of the conditioning column consisting of at least two stages, the circulating process gas condensate is cooled, which in turn cools the flue gas, resulting in the formation of further acidic process gas condensate. This acidic process gas condensate is used in the acid scrubbing (9) of the process.This allows the use of sulfuric acid in the acid scrubbing to be advantageously reduced. In the second stage (7) of the conditioning, alkali is preferably added, and a conditioned process gas is obtained. The acidic process gas condensate obtained in the first stage (6) of the at least two-stage conditioning is fed completely or partially to a scrubbing column (9) downstream of the absorber column (8) or to a scrubbing stage (9) within the absorber column (8). This results in an acidic process gas condensate enriched with amines and nitrogenous decomposition products of the amines.
[0073] Alternatively or additionally, the acidic process gas condensate is fed completely or partially to an acid scrubber (4) located upstream of the conditioning column. In the acid scrubber (4), ammonia-enriched water is obtained and directed to the combustion chamber (1). This is advantageous if the CCh-emitting plant is a CCh-emitting plant with selective non-catalytic reduction technology, as this allows the use of ammonia, ammonia water (aqueous ammonia solution), or amines for NOx reduction, which is necessary in the process, to be partially or completely replaced. According to an alternative embodiment, the ammonia-enriched water obtained in the acid scrubber (4) is fed upstream of a catalyst layer. This is advantageous if the CCh-emitting plant is a CO2-
[0074] RK / RK 240604WO February 5, 2026. This is an emitting plant with selective catalytic reduction technology, as this allows the use of ammonia, ammonia water (aqueous ammonia solution), or amines for NOx reduction, which is necessary in the process, to be partially or completely replaced. The conditioned process gas obtained in the second stage (7) of the at least two-stage conditioning process is fed into the absorber column (8). Process gas condensate from the second stage (7) of the at least two-stage conditioning process is advantageously used as make-up water for cooling towers or make-up water for scrubbers. Possible application locations for the process gas condensate from the second stage (7) are shown with dashed lines in the figure. The conditioned process gas is brought into contact with an amine-containing absorbent in the absorber column, which is regenerated in a desorber column (not shown in the figure) and returned to the absorber column after cooling.The amine-containing absorbent removes CO2 from the process gas. The CCh-deficient process gas is then fed to the washing column (9) downstream of the absorber column (8) or to the washing stage (9) within the absorber column (8).
[0075] Reference symbol list:
[0076] 1 combustion chamber
[0077] 2 steam generators
[0078] 3 Process gas purification
[0079] 4 acid wash
[0080] 5 fireplace
[0081] 6. First stage of conditioning
[0082] 7. Second stage of conditioning
[0083] 8 absorber column
[0084] 9 Washing column / Washing stage
[0085] RK / RK 240604WO February 5, 2026
Claims
February 5, 2026 Patent claims 1. A process for removing acidic gases from a process gas of a CO2-emitting plant using an amine-containing absorbent, which is brought into contact with the process gas in an absorber column and which is regenerated in a desorber column and returned to the absorber column after cooling, characterized in that the process gas undergoes at least two-stage conditioning in a conditioning column before being brought into contact with the amine-containing absorbent, wherein in the first stage of conditioning the process gas is cooled, yielding an acidic process gas condensate, and in the second stage of conditioning a conditioned process gas is obtained, wherein i] the acidic process gas condensate is fed completely or partially to a washing column downstream of the absorber column or to a washing stage in the absorber column, resulting in an acidic process gas condensate enriched with amines and nitrogenous decomposition products of the amines, and / or ii] the acidic process gas condensate is fed completely or partially to a washing column upstream of the conditioning column.
2. A method according to claim 1, characterized in that the process gas condensate enriched with amines and nitrogenous decomposition products of the amines comprises ammonia.
3. A method according to claim 1 or 2, characterized in that the process gas condensate enriched with amines and nitrogenous decomposition products of the amines, in particular ammonia, is fed into a combustion chamber in a CCh-emitting plant with selective non-catalytic reduction technology.
4. Method according to claim 3, characterized in that the process gas condensate enriched with amines and nitrogenous decomposition products of the amines, in particular ammonia, is supplied to the combustion chamber at a temperature between 850°C and 1050°C.
5. Method according to claim 1 or 2, characterized in that the process gas condensate enriched with amines and nitrogenous decomposition products of the amines, in particular ammonia, is fed into a CCh-emitting plant with selective catalytic reduction technology upstream of a catalyst layer.
6. Method according to claim 5, characterized in that the process gas condensate enriched with amines and nitrogenous decomposition products of the amines, in particular ammonia, is supplied before the catalyst layer at a temperature between 170°C and 380°C.
7. Method according to one of claims 1 to 6, characterized in that the CCh-emitting plant is selected from residual material incineration plants, waste incineration plants, sewage sludge incineration plants, biomass incineration plants, CCh-emitting plants of power plants, CCh-emitting plants of petrochemical plants, CCh-emitting plants of cement plants and CCh-emitting plants of steel plants as well as other metal processing plants. RK / RK 240604WO February 5, 20268. Method according to one of claims 1 to 7, characterized in that in the first stage of the at least two-stage conditioning column the process gas is cooled to a temperature below the water dew point, in particular to a temperature between 30 and 75°C.
9. Method according to claim 8, characterized in that the cooling in the first stage of the at least two-stage conditioning column is carried out by means of circulating process gas condensate, preferably cooled by means of a cooler or heat pump.
10. Method according to one of claims 1 to 9, characterized in that in the absorber column the amine-containing absorbent CO2 is absorbed from the conditioned process gas and the CCh-poor conditioned process gas is fed to the washing column downstream of the absorber column or to the washing stage in the absorber column.
11. Method according to one of claims 1 to 10, characterized in that the CO2 is separated from the amine-containing absorbent in the desorber column.
12. Method according to one of claims 1 to 11, characterized in that an alkali, in particular sodium hydroxide, is added in the second stage of the two-stage conditioning column.
13. CC-emitting plant, comprising a gas scrubbing device for process gases of the CCh-emitting plant, wherein the gas scrubbing device comprises at least one process gas path, a first scrubbing column, optionally further process gas scrubbing columns, a conditioning column of at least two stages downstream of the first scrubbing column or the optional further process gas scrubbing columns, a CCh separation unit with an absorber column, optionally comprising integrated flue gas cleaning technologies, and a RK / RK 240604WO February 5, 2026 Desorber column and a second washing column downstream of the absorber column or an absorber column comprising an absorber stage and a washing stage, characterized in that (i) the conditioning column, which has at least two stages, is connected to the second washing column downstream of the absorber column or to the washing stage of the absorber column in such a way that an acidic process gas condensate stream from the first stage of the conditioning column, which has at least two stages, is directed wholly or partly into the second washing column downstream of the absorber column or into the washing stage of the absorber column, and / or (h) the conditioning column, which has at least two stages, is connected to the first washing column in such a way that a process gas condensate stream from one of the two stages of the conditioning column, which has at least two stages, is directed wholly or partly into the first washing column.
14. CCh-emitting plant according to claim 13, characterized in that the CCh-emitting plant is a CCh-emitting plant with selective non-catalytic reduction technology, wherein the second washing column downstream of the absorber column or the washing stage of the absorber column is connected to a combustion chamber of the CCh-emitting plant in such a way that a process gas condensate stream enriched with amines and nitrogenous decomposition products of the amines, in particular ammonia, is directed from the second washing column downstream of the absorber column or the washing stage of the absorber column into the combustion chamber of the CCh-emitting plant. RK / RK 240604WO February 5, 202615. CCh-emitting plant according to claim 13, characterized in that the CCh-emitting plant is a CCh-emitting plant with selective catalytic reduction technology, which has at least one catalyst layer for removing nitrogen oxides from the process gas, wherein the second scrubbing column downstream of the absorber column or the scrubbing stage of the absorber column is connected to the catalyst layer in such a way that a process gas condensate stream enriched with amines and nitrogenous decomposition products of the amines, in particular ammonia, is injected from the second scrubbing column downstream of the absorber column or the scrubbing stage of the absorber column upstream of the catalyst layer.
16. Use of a process gas condensate from a combustion plant enriched with amines and nitrogenous decomposition products of the amines, in particular ammonia, for the reduction of nitrogen oxides in a process gas of a CCh-emitting plant with selective non-catalytic reduction technology or with selective catalytic reduction technology. RK / RK 240604WO February 5, 2026