DE102008013738A1 - Deacidifying gaseous liquid stream containing acid gases as impurities, comprises contacting liquid stream with detergent containing (aqueous) solution of alkanolamine and ionic liquid/hyperbranched polymers, and purifying liquid stream - Google Patents

Abstract

Process for deacidification of a gaseous liquid stream containing acid gases as impurities, comprises contacting the liquid stream with a detergent in at least one absorption step, where the detergent contains an aqueous or non-aqueous solution containing one or more alkanolamines and ionic liquids or hyperbranched polymers; purifying the liquid stream by acid gases and separating the detergent loaded with acid gases. An independent claim is included for a detergent for deacidification of a gaseous liquid stream containing acid gases comprising the alkanolamine(s) and the ionic liquids or at least the hyperbranched polymer, where: the detergent further contains water and the ionic liquid is stable under the process conditions of the gas wash and the regeneration of the detergent, and the ionic liquid or the hyperbranched polymer in considerable mass dissolves the acid gas component to be removed.

Description

The The present invention relates to a process for deacidification a gas stream containing acid gases as impurities, and a detergent for use in such a process.

In industry, a variety of acidic gas mixtures such. B. CO, CO2, H2S, SO2, CS2, HCN, COS or mercaptans, from which using a suitable detergent (also called absorbent) selectively components of the gas or vapor mixture (the absorptive or the absorptive) are removed. These fluid streams may be, for example, gas streams (such as natural gas, synthesis gas, refinery gas, biogas) or liquid or liquefied hydrocarbon streams or NGL (natural gas liquids) or exhaust gas streams from fossil power plants. For example, CO2 has to be removed from natural gas because high concentrations of CO2 reduce the calorific value of the gas. In addition, CO2 can lead to corrosion on pipes with water. The preferred dissolved in the absorbent gas or vapor component (s) are called absorptive. The underlying process, absorption, is used to separate or purify gas mixtures. The state of the art is summarized by the authors Sattler and Gmehling and Brehm [ Sattler, K., Thermal Separation Methods, ISBN 3-527-28636-5, Chapter 3 and Gmehling J., Brehm A., Basic Operations, Textbook of Technical Chemistry - Volume 2, ISBN 3-13-687401-3 ].

In 1 a typical combination of absorber (AS) and desorber (DS) is shown. The raw gas or gaseous fluid RG to be purified enters the absorber and is purified by means of the regenerated detergent or absorbent RL, which may need to be supplemented due to losses with the stream LE, and freed of entrained liquid droplets in the liquid separator AB. This will be the clean gas GG. For economy, the heat exchangers WL1 and WL2 are used. In the Desorberteil DS the loaded detergent BL is freed from the loading with absorptive. As a rule, heat is supplied below in the absorber via the heat exchanger WV. Also, circuits with inert gases supplied at the bottom of the desorber DS are known or by applying vacuum to DS. A regeneration of the detergent in several successive substeps, for example, in US 4336233 disclosed.

Around Limiting detergent losses is at the head of DS a partial condenser WK installed. The exhaust gas flow AG consists of the absorbed components in BL and any losses of detergent. The regenerated detergent RL is returned to the apparatus AS.

The efficiency of an absorption process depends essentially on the properties of the detergent used. Thus, the selectivity, capacity, flash point, thermal and chemical stability of the absorbent should be as high as possible and the vapor pressure, viscosity and corrosiveness should be as low as possible [ Gmehling J., Brehm A., Basic Operations, Textbook of Technical Chemistry - Volume 2, ISBN 3-13-687401-3 ]. The separation cost of an absorption process is reflected in the so-called solvent ratio, the quotient of unloaded amount of absorbent and inert carrier gas. With increasing solvent ratio, the solvent-related operating costs increase, while the number of absorber stages and investment costs for the absorber decrease [ Sattler, K., Thermal Separation Methods, ISBN 3-527-28636-5, Chapter 3 ]. The better the absorption capacity of an absorbent for the gas component to be absorbed, the smaller the solvent ratio. As a measure of this capacity, the Henry constant can be used. This is the smaller, the greater the gas solubility in the considered detergent.

Therefore, a small Henry constant is desirable. To determine the Henry constant, experimental phase equilibrium data must be used for the respective gas / absorbent system. The Henry constant H _{1,2 of} the solute 1 in the absorbent 2 results from the slope of the fugacity for a molar fraction of the component 1 approaching zero, ie simplified at the saturation vapor pressure of the absorbent 2 [ Gmehling J., Kolbe B., Thermodynamics, ISBN 3-527-28547-4, Chapter 4 ]. The various experimental methods for determining the Henry constant are given in [ Prausnitz JM, Lichtenthaler RN, de Azevedo EG, Molecular Thermodynamics of Fluid-Phase Equilibria, ISBN 0-13-977745-8 ; Gmehling J., Kolbe B., Thermodynamics, ISBN 3-527-28547-4 and Stephan K., Mayinger F., Thermodynamics - Volume 2 multi-component systems and chemical reactions, ISBN 3-540-54459-3 ] and are used in this patent.

It Both physical and chemical detergents are used.

An example of the physical absorption is in US20060251558 described. The detergent is an ionic liquid.

The mode of action of chemical detergents is based on chemical reactions of the detergent in which, after absorption, the dissolved acid gases are present in the form of chemical compounds. For example, the most commonly used as chemical solvents in the industrial scale aqueous solutions of inorganic rule bases when dissolving sour gases practically non-volatile ions formed. Today, alkanolamines such as monoethanolamine (MEA, 2-aminoethanol), diethanolamine (DEA), triethanolamine (TEA), diethylethanolamine (DEEA), diisopropylamine (DIPA), aminoethoxyethanol (AEE), methyldiethanolamine (MDEA), are used to remove acid gas contaminants from gaseous fluid streams. 2- (aminoethyl) ethanolamine (AEEA) and 2-amino-2-methyl-1-propanol (AMP).

primary and secondary alkanolamines are especially for Gas washes suitable, in which the purified gas a very low CO2 content. It will be soluble Carbamate, so distinguishable chemical species, formed. This is the reason for the low achievable partial pressure.

To the Regeneration of the amine solution is used in industrial applications often a multi-stage regeneration process, that is several apparatus DS, using the loaded solvent BL initially relaxed in flash columns, leaving a part the absorbed CO2 evaporates from the solution. remaining Carbon dioxide and possibly other absorbed acid gases then by stripping with steam in a second apparatus DS removed. Should portions of the amine solution in the desorbed Sour gas is not included, a third DS is needed. Solvents, the primary and secondary Alkanolamines require one to decompose the carbamate Minimum temperature and a larger amount of heat as tertiary amines and in particular a multiple amount of heat compared to physical detergents.

The European patent application EP-A 0 322 924 discloses an aqueous amine solution which may contain tertiary alkanolamines, especially MDEA, for deacidifying gas streams.

A disadvantage of all described detergents is the fact that they are more or less volatile, which means that the detergent with the purified fluid stream GG is partially discharged from the absorber AS. The same thing happens in the Desorber DS. Again, for scientific reasons prior to prior disclosure of this invention, the desorbed gas AG must contain the detergent. This detergent is called the primary detergent. The disadvantages are: loss of primary detergent and contamination of both gas streams. The problem of contamination is particularly serious when one of the gas streams, here the gas stream from the absorber, is discharged into the environment. This is regularly the case with the removal of CO2 from flue gases of fossil power plants. As a countermeasure, another absorber after the actual absorber or desorber is installed, which largely reduces the proportions of the primary detergent with another detergent, the secondary detergent. In 1 Thus, the flows GG and AG are fluid streams that enter another absorber. In the case of the flue gas scrubbing, the secondary scrubbing agent is water which can be released with the purified fluid gas stream from the further absorber to the environment. The added secondary detergent contaminated with the primary detergent, however, must be cleaned again, which means an increased heat demand and equipment.

The The invention relates to a method which has this additional Effort is avoided as it is the use of a secondary Makes detergent superfluous. Also prevented the novel detergent emissions in the desorber and. The solution the problem consists in a novel detergent, which in addition the known alkanolamines contains an additive, the volatility of the primary detergent considerably reduced. The additive itself has an extremely low Vapor pressure on. In an embodiment of the invention Detergent is an additive ionic liquid or a mixture of different ionic liquids used.

In Another embodiment of the invention is an inventive Washing liquid proposed as non-volatile Additive contains a hyperbranched polymer. Not Any high-boiling liquid is suitable, because it should the necessary amount of detergent is not or only slightly increased become. This may be due to the same or similar Henry constants be read. Due to the high heat demand should the inventive detergent a lower Have absorption heat as without additive. Surprised It was found that these seemingly contradictory requirements by hyperbranched polymers or ionic liquids can be met.

By ionic liquids are meant liquid salts having melting points below 100 ° C [ Wasserscheid, P .; Keim, W .; Angewandte Chemie 2000, 112, 3926-3945 ]. Due to the high variation in the structure of their cations and anions, their physico-chemical properties, in particular their solubility and mixing properties can be varied within wide limits. Many ionic liquids have very good solubility for a large number of organic, inorganic and polymeric substances. In addition, ionic liquids are usually non-flammable, non-corrosive and less viscous and are characterized by an extremely low vapor pressure.

Among hyperbranched polymers in the application DE 10 2006 012 353 understood substances understood.

The inventive method can be used with typical for gas scrubbing and subsequent regeneration of the detergent system configurations as in 1 be performed as shown for example in US 4,336,233 for a single-stage or two-stage washing process and particularly detailed in EP-A 0 322 924 are described for a one-step washing process with relaxation and desorption step. In a claimed embodiment of the method according to the invention, the detergent consists of an alkanolamine or a mixture of several alkanolamines and an ionic liquid, wherein the detergent may contain water. The ionic liquid is stable under the process conditions of gas scrubbing and regeneration of the scrubbing agent and, in itself, has a considerable ability to dissolve the acid gas component to be separated. Therefore, as indirectly demonstrated in Example 2, the capacity is significantly increased. Increased capacity for the same amount and heat of reaction results in a lower amount of detergent needed for a given separation task.

• – quarternären Ammonium-Kationen der allgemeinen Formel [NR¹R²R³R]⁺,
• – Phosphonium-Kationen der allgemeinen Formel [PR¹R²R³R]⁺,
• – Imidazolium-Kationen der allgemeinen Formel
  
  wobei der Imidazol-Kern substituiert sein kann mit wenigstens einer Gruppe, die ausgewählt ist aus C₁-C₆-Alkyl-, C₁-C₆-Alkoxy-, C₁-C₆-Aminoalkyl-, C₅-C₁₂-Aryl- oder C₅-C₁₂-Aryl-C₁-C₆-Alkylgruppen,
• – Pyridinium-Kationen der allgemeinen Formel
  
  wobei der Pyridin-Kern substituiert sein kann mit wenigstens einer Gruppe, die ausgewählt ist aus C₁-C₆-Alkyl-, C₁-C₆-Alkoxy-, C₁-C₆-Aminoalkyl-, C₅-C₁₂-Aryl- oder C₅-C₁₂-Aryl-C₁-C₆-Alkylgruppen,
• – Pyrazolium-Kationen der allgemeinen Formel
  
  wobei der Pyrazol-Kern substituiert sein kann mit wenigstens einer Gruppe, die ausgewählt ist aus C₁-C₆-Alkyl-, C₁-C₆-Alkoxy-, C₁-C₆-Aminoalkyl-, C₅-C₁₂-Aryl- oder C₅-C₁₂-Aryl-C₁-C₆-Alkylgruppen,
• – und Triazolium-Kationen der allgemeinen Formel
  
  wobei der Triazol-Kern substituiert sein kann mit wenigstens einer Gruppe, die ausgewählt ist aus C₁-C₆-Alkyl-, C₁-C₆-Alkoxy-, C₁-C₆-Aminoalkyl-, C₅-C₁₂-Aryl- oder C₅-C₁₂-Aryl-C₁-C₆-Alkylgruppen, und die Reste R¹, R², R³ unabhängig voneinander ausgewählt sind aus der Gruppe bestehend aus
• – Wasserstoff;
• – linearen oder verzweigten, gesättigten oder ungesättigten, aliphatischen oder alicyclischen Alkylgruppen mit 1 bis 20 Kohlenstoffatomen;
• – Heteroaryl-, Heteroaryl-C₁-C₆-Alkylgruppen mit 3 bis 8 Kohlenstoffatomen im Heteroaryl-Rest und wenigstens einem Heteroatom ausgewählt aus N, O und S, der mit wenigstens einer Gruppe ausgewählt aus C₁-C₆-Alkylgruppen und/oder Halogenatomen substituiert sein können;
• – Aryl-, Aryl-C₁-C₆-Alkylgruppen mit 5 bis 12 Kohlenstoffatomen im Arylrest, die gegebenenfalls mit wenigstens einer C₁-C₆-Alkylgruppen und/oder einem Halogenatomen substituiert sein können; und der Rest R ausgewählt ist aus
• – linearen oder verzweigten, gesättigten oder ungesättigten, aliphatischen oder alicyclischen Alkylgruppen mit 1 bis 20 Kohlenstoffatomen;
• – Heteroaryl-C₁-C₆-Alkylgruppen mit 4 bis 8 Kohlenstoffatomen im Arylrest und wenigstens einem Heteroatom ausgewählt aus N, O und S, die mit wenigstens einer C1-C6-Alkylgruppen und/oder Halogenatomen substituiert sein können;
• – Aryl-C₁-C₆-Alkylgruppen mit 5 bis 12 Kohlenstoffatomen im Arylrest, die gegebenenfalls mit wenigstens einer C₁-C₆-Alkylgruppe und/oder einem Halogenatomen substituiert sein können.

The detergent of the invention, without accounting for the water, contains between 0.1 and 90% by mass of the ionic liquid, preferably between 10 and 85% by mass of the ionic liquid, most suitably between 50 and 80% by mass of the ionic liquid relative to the total solution. The claimed embodiment of the detergent and method according to the invention is further proposed that the ionic liquid used is a compound of the formula [A] n + [Y] n-,
where n = 1 or 2 and
the anion [Y] ^{n- is} selected from the group
from tetrafluoroborate ([BF ₄ ] ^- ), hexafluorophosphate ([PF ₆ ] ^- ), dicyanamide ([N (CN) ₂ ] ^- ), tricyanomethide ([C (CN) ₃ ] ^- , tetracyano borate ([B (CN) ₄ ] ^-, halides (Cl ^-, Br ^-, F ^-, I ^-), hexafluoroantimonate ([SbF _6] ^-), sulfate ([SO _4] ^2-), tosylate ([C ₇ H ₇ SO _3] ^-), Triperfluoroethyl trifluorophosphate ([PF ₃ (C ₂ F ₅ ) ₃ ] ^- ), thiocyanate ([SCN] -), carbonate ([CO ₃ ] ^2- ), fluorosulfonate, [R'-COO] _, [R ' SO ₃ ] ^- , [R'PO ₄ R "'] or [(R'-SO ₂ ) ₂ N] -, and R' and R" are identical or different, each containing a linear or branched aliphatic 1 to 12 carbon atoms or alicyclic alkyl or C ₅ -C ₁₈ aryl, C ₅ -C ₁₈ aryl, C ₁ -C ₆ alkyl or C ₁ -C ₆ alkyl, C ₅ -C ₁₈ aryl which may be substituted by halogen atoms, in particular fluorine atoms,
the cation [A] + is selected from

• Quaternary ammonium cations of the general formula [NR ¹ R ² R ³ R] ⁺ ,
• Phosphonium cations of the general formula [PR ¹ R ² R ³ R] ⁺ ,
• - Imidazolium cations of the general formula
  
  wherein the imidazole nucleus may be substituted with at least one group selected from C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy, C ₁ -C ₆ aminoalkyl, C ₅ -C ₁₂ - Aryl or C ₅ -C ₁₂ -aryl-C ₁ -C ₆ -alkyl groups,
• - Pyridinium cations of the general formula
  
  wherein the pyridine nucleus may be substituted with at least one group selected from C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy, C ₁ -C ₆ aminoalkyl, C ₅ -C ₁₂ - Aryl or C ₅ -C ₁₂ -aryl-C ₁ -C ₆ -alkyl groups,
• - Pyrazolium cations of the general formula
  
  wherein the pyrazole nucleus may be substituted with at least one group selected from C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy, C ₁ -C ₆ aminoalkyl, C ₅ -C ₁₂ - Aryl or C ₅ -C ₁₂ -aryl-C ₁ -C ₆ -alkyl groups,
• - And triazolium cations of the general formula
  
  wherein the triazole nucleus may be substituted with at least one group selected from C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy, C ₁ -C ₆ aminoalkyl, C ₅ -C ₁₂ - Aryl or C ₅ -C ₁₂ aryl-C ₁ -C ₆ alkyl groups, and the radicals R ¹ , R ² , R ^{3 are} independently selected from the group consisting of
• - hydrogen;
• - linear or branched, saturated or unsaturated, aliphatic or alicyclic alkyl groups having 1 to 20 carbon atoms;
• - heteroaryl, heteroaryl-C ₁ -C ₆ alkyl groups having 3 to 8 carbon atoms in the heteroaryl radical and at least one heteroatom selected from N, O and S, which is at least one group out may be selected from C ₁ -C ₆ alkyl groups and / or halogen atoms;
• - aryl, aryl-C ₁ -C ₆ -alkyl groups having 5 to 12 carbon atoms in the aryl radical, which may optionally be substituted by at least one C ₁ -C ₆ -alkyl group and / or one halogen atom; and the remainder R is selected
• - linear or branched, saturated or unsaturated, aliphatic or alicyclic alkyl groups having 1 to 20 carbon atoms;
• - heteroaryl-C ₁ -C ₆ -alkyl groups having 4 to 8 carbon atoms in the aryl radical and at least one heteroatom selected from N, O and S, which may be substituted by at least one C ₁ -C ₆ -alkyl groups and / or halogen atoms;
• - Aryl-C ₁ -C ₆ alkyl groups having 5 to 12 carbon atoms in the aryl radical, which may be optionally substituted with at least one C ₁ -C ₆ alkyl group and / or a halogen atom.

In a preferred embodiment of the invention Method dissolves the ionic liquid used with more than 10% by mass in the alkanolamine used and forms while a washing liquid whose viscosity less than 100 mPas at 25 ° C.

In a particularly preferred embodiment of the invention Process is called alkanolamine monoethanolamine (MEA) and as ionic Liquid used a methylsulfonate salt.

In a further particularly preferred embodiment of the inventive method is called alkanolamine Monoethanolamine (MEA) and as an ionic liquid Trifluoromethylsulfonat used.

In a further particularly preferred embodiment of the inventive method is called alkanolamine Monoethanolamine (MEA) and as an ionic liquid Dialkyl phosphate salt used.

In a further particularly preferred embodiment of the inventive method is called alkanolamine Monoethanolamine (MEA) and as an ionic liquid Phosphonium salt used.

In a further particularly preferred embodiment of the inventive method is called alkanolamine Monoethanolamine (MEA) and as an ionic liquid 1,3-Dialkylimidazoliumsalz used.

In a further particularly preferred embodiment of the inventive method is called alkanolamine Monoethanolamine (MEA) and as an ionic liquid 1,2,3-Trialkylimidazoliumsalz used.

In a variant of the inventive method the detergent contains an ionic liquid, which itself contains an alkanolamine function.

In a further claimed embodiment of the invention Procedure, the detergent consists of an alkanolamine or a Mixture of several alkanolamines and one hyperbranched polymer, wherein the detergent may contain water.

The Detergent according to the invention contains between 0.1 and 90% by mass of the hyperbranched polymer, preferred between 10 and 85% by mass of the hyperbranched polymer, most suitably, however, between 50 and 80% by mass of the hyperbranched Polymer.

In a preferred variant of this embodiment of the invention Method, the hyperbranched polymer used has miscibility with the alkanolamine used of more than 10 percent by mass Polymer on alkanolamine. The hyperbranched polymer is among the Process conditions of gas scrubbing and regeneration of the Detergent stable and owns itself to a considerable extent the ability to segregate the sour gas component to solve. The washing liquid consisting of hyperbranched Polymer and alkanolamine has a viscosity of below 100 mPas at 25 ° C.

in the The invention will now be described by way of examples and comparative examples explained in more detail.

Comparative Example 1

In This example illustrates the high volatility of the alkanolamine based on measurements. Pure MEA shows at 79 ° C a vapor pressure of 21 mbar. That means that in an exhaust stream GG, which has a pressure of exemplarily 1000 mbar at 79 ° C and that follows the equation of state of the ideal gas, the current GG with pure MEA as detergent RL from 2.1 mol% MEA and 97.9% Clean gas would exist. This is a big loss, though one compares with flue gas scrubbing with 1000 kg / s exhaust gas flow GG. In a gas stream that is released to the environment, this is Proportion of alkanolamine too high.

example 1

To demonstrate the partial pressure reduction of the detergent according to the invention containing as non-volatile additive an ionic liquid, a mixture of 32% by mass of MEA and 68% by mass of the ionic liquid [EMIM] [CH ₃ SO ₃ ]. Since the ionic liquid had no measurable vapor pressure in the experiment, the measured pressure at 79 ° C is again the partial pressure of MEA. There were measured 6.4 mbar, that is less than 1/3 relative to Comparative Example 1. Thus, the loss of detergent in absorption / desorption is about 1/3 lower.

Comparative Example 2

The solubility of an acid gas component, in this case CO ₂ , is determined in a typical aqueous alkanolamine, here a solution of 29% by mass of MEA and 71% by mass of water. The result is reported in the form of Henry's constants in the physical unit MPa. temperature Henry Constant 50 1.2 65 1.4 79.5 1.6

The solubility is also explained by the chemical reaction of monoethanolamine with CO ₂ in the aqueous medium according to OH-CH ₂ -CH ₂ -NH ₂ + CO ₂ + H ₂ O⇔OH-CH ₂ -CH ₂ -NH + / 3 + HCO- / 3

Example 2

To demonstrate the advantages of the process according to the invention, the solubility of an acid gas component, here CO ₂ , in a detergent according to the invention consisting of 30 mass% MEA and 70 mass% of the ionic liquid [EMIM] [CH ₃ SO ₃ ] was determined. temperature Henry Constant 51 1.2 66 1.4 78.4 1.6

It it is clear that the advantages of the comparative example 2 are preserved, but it is according to the teaching of the example 1, the partial pressure of alkanolamine in the clean gas reduced by about 1/3.

In the non-aqueous system studied, the reaction equilibrium is different compared to Comparative Example 2: 2OH-CH ₂ -CH ₂ -NH ₂ + CO ₂ ⇔OH-CH ₂ -CH ₂ -NH + / 3 + OH-CH ₂ -CH ₂ -NH-COO ^-

In this reaction, 2 molecules of alkanolamine per absorbed molecule of CO _{2 are} needed. Nevertheless, the Henry constant and thus the capacity for Comparative Example 2 is surprisingly identical. The existence of the carbamate compound was confirmed by NMR spectroscopy.

Example 3

To clarify that the detergent according to the invention may also contain other ionic liquids selected according to the above-mentioned features, Example 2 was repeated with the ionic liquid [EMIM] [CF ₃ SO ₃ ]. For this purpose, the solubility of an acid gas component, in this case CO ₂ , in a detergent according to the invention consisting of 30% by mass of MEA and 70% by mass of the ionic liquid [EMIM] [CF ₃ SO ₃ ] was determined. temperature Henry Constant 51 1.8 64.5 1.9 79.4 2.2

This Example shows that the above-mentioned rule is the ionic liquid is to be chosen so that they as pure substance as high as possible Has acid gas solubility.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• US 4336233 [0003, 0018]
• US 20060251558 [0008]
• - EP 0322924 A [0012, 0018]
• - DE 102006012353 [0017]

Cited non-patent literature

• - Sattler, K., Thermal Separation Methods, ISBN 3-527-28636-5, Chapter 3 and Gmehling J., Brehm A., Basic Operations, Textbook of Technical Chemistry - Volume 2, ISBN 3-13-687401-3 [0002]
• - Gmehling J., Brehm A., Basic Operations, Textbook of Technical Chemistry - Volume 2, ISBN 3-13-687401-3 [0005]
• - Sattler, K., Thermal Separation Methods, ISBN 3-527-28636-5, Chapter 3 [0005]
• - Gmehling J., Kolbe B., Thermodynamics, ISBN 3-527-28547-4, Chapter 4 [0006]
• Prausnitz JM, Lichtenthaler RN, de Azevedo EG, Molecular Thermodynamics of Fluid-Phase Equilibria, ISBN 0-13-977745-8 [0006]
• - Gmehling J., Kolbe B., Thermodynamics, ISBN 3-527-28547-4 [0006]
• - Stephan K., Mayinger F., Thermodynamics - Volume 2 multi-component systems and chemical reactions, ISBN 3-540-54459-3 [0006]
• - Wasserscheid, P .; Keim, W .; Angewandte Chemie 2000, 112, 3926-3945 [0016]

Claims (25)

Method for deacidifying a gaseous fluid stream, contains the acid gases as impurities, wherein in at least one absorption step, the fluid flow with a detergent brings into intimate contact, which is an aqueous or non-aqueous solution containing a) one or more Alkanolamines, b) ionic liquids, and man the largely purified of acid gases fluid stream and with Acid gases laden detergent separated from each other. A process for deacidifying a fluid stream, the Contains acid gases as impurities, wherein in at least an absorption step, the fluid flow with a detergent in brings in intimate contact, which is an aqueous or non-aqueous solution containing a) an or a plurality of alkanolamines, b) hyperbranched polymers, and the largely purified of acid gases fluid stream and with Acid gases laden detergent separated from each other. The method of claim 1, wherein the concentration on ionic liquid, without mathematical consideration of water, between 0.1 and 90% by mass of ionic liquid, preferably between 10 and 85% by mass of ionic liquid, most suitably, however, is between 50 and 80% by mass of ionic Contains liquid The method of claim 2, wherein the concentration on hyperbranched polymer, without mathematical consideration of water, between 0.1 and 90% by mass of hyperbranched Polymer, preferably between 10 and 85% by mass of hyperbranched Polymer, most suitably between 50 and 80 mass percent contains hyperbranched polymer. Method according to one of the claims 1 to 4, wherein the absorption step at a total pressure of 0.5 bar or a higher pressure is made. Method according to one of the claims 1 to 5, characterized in that the detergent is followed thermally regenerated and then fed again to the absorption apparatus. Process according to claim 6, characterized in that that you regenerate the detergent by relaxing. Process according to claim 6, characterized in that that you can use the detergent after relaxing by stripping with an inert fluid, in particular nitrogen or water vapor, regenerated. Method according to one of the claims 1 to 6, characterized in that the absorption step in consecutive sub-steps, wherein the sauergashaltigen fluid stream in each of the substeps with a Partial stream of the detergent contacted. Claimed is a detergent for deacidification a gaseous fluid stream containing acid gases, characterized in that the detergent aa) an alkanolamine or a mixture of several alkanolamines, and bb) at least one Contains ionic liquid. a) the detergent additionally may contain water b) the detergent contains at least one ionic liquid, under the process conditions of gas scrubbing and the Regeneration of the detergent is stable. c) This ionic Liquid itself to a considerable extent the ability has to dissolve the sour gas component to be separated. Detergent according to claim 10, wherein the concentration on ionic liquid, without mathematical consideration of water, between 0.1 and 90% by mass of ionic liquid, preferably between 10 and 85% by mass of ionic liquid, most suitably, however, is between 50 and 80% by mass of ionic Contains liquid Detergent according to claims 10 to 11, which contains at least one ionic liquid of the formula [A] n + [Y] n-, where n = 1 or 2 and the anion [Y] n- is selected from the group consisting of tetrafluoroborate ([BF4 ] -), hexafluorophosphate ([PF6] -), dicyanamide ([N (CN) 2] -), tricyanomethide ([C (CN) 3] -, tetracyano borate ([B (CN) 4] -, halides (Cl- , Br, F, I), hexafluoroantimonate ([SbF6] -), sulfate ([SO4] 2-), tosylate ([C7H7SO3] -), triperfluoroethyl trifluorophosphate ([PF3 (C2F5) 3] -), Thiocyanate ([SCN] -), carbonate ([CO3] 2-), fluorosulfonate, [R'-COO] -, [R'-SO3] -, [R'PO4R ''] or [(R'-SO2) 2N] -, and R 'and R "are the same or different, each containing a linear or branched 1 to 12 carbon atoms aliphatic or alicyclic alkyl or a C5-C18-aryl, C5-C18-aryl-C1-C6-alkyl - or C1-C6-alkyl-C5-C18-aryl radical which may be substituted by halogen atoms, in particular fluorine atoms, the cation [A] + is selected from - quart ammonium ammonium cations of the general formula [NR1R2R3R] +, - phosphonium cations of the general formula [PR1R2R3R] +, - imidazolium cations of the general formula

wherein the imidazole nucleus may be substituted with at least one group selected from C1-C6-alkyl, C1-C6-alkoxy, C1-C6-aminoalkyl, C5-C12-aryl or C5-C12-aryl -C1-C6-alkyl groups, - pyridinium cations of the general formula

wherein the pyridine nucleus may be substituted with at least one group selected from C1-C6-alkyl, C1-C6-alkoxy, C1-C6-aminoalkyl, C5-C12-aryl or C5-C12-aryl -C1-C6-alkyl groups, - pyrazolium cations of the general formula

wherein the pyrazole nucleus may be substituted with at least one group selected from C1-C6-alkyl, C1-C6-alkoxy, C1-C6-aminoalkyl, C5-C12-aryl or C5-C12-aryl -C1-C6-alkyl groups, - and triazolium cations of the general formula

wherein the triazole nucleus may be substituted with at least one group selected from C1-C6-alkyl, C1-C6-alkoxy, C1-C6-aminoalkyl, C5-C12-aryl or C5-C12-aryl -C1-C6-alkyl groups, and the radicals R1, R2, R3 are independently selected from the group consisting of - hydrogen; - linear or branched, saturated or unsaturated, aliphatic or alicyclic alkyl groups having 1 to 20 carbon atoms; - Heteroaryl, heteroaryl-C1-C6-alkyl groups having 3 to 8 carbon atoms in the heteroaryl radical and at least one heteroatom selected from N, O and S, which are substituted with at least one group selected from C1-C6-alkyl groups and / or halogen atoms can; - Aryl, aryl-C1-C6-alkyl groups having 5 to 12 carbon atoms in the aryl radical, which may be optionally substituted with at least one C1-C6-alkyl groups and / or a halogen atom; and the radical R is selected from: linear or branched, saturated or unsaturated, aliphatic or alicyclic alkyl groups having 1 to 20 carbon atoms; - heteroaryl-C1-C6-alkyl groups having 4 to 8 carbon atoms in the aryl radical and at least one heteroatom selected from N, O and S, which may be substituted by at least one C1-C6-alkyl groups and / or halogen atoms; - Aryl-C 1 -C 6 -alkyl groups having 5 to 12 carbon atoms in the aryl radical, which may optionally be substituted by at least one C 1 -C 6 -alkyl group and / or a halogen atom. Detergent according to claims 10 to 12, which contains at least one ionic liquid, soluble with more than 10 percent by mass in the alkanolamine used is and thereby forms a washing liquid whose viscosity less than 100 mPas at 25 ° C. Detergent according to claims 10-13, which as an ionic liquid is a methylsulfonate salt contains. Detergent according to claims 10-13 containing as an ionic liquid a trifluoromethylsulfonate salt contains. Detergent according to claims 10 to 13, which is a dialkyl phosphate salt as an ionic liquid contains. Detergent according to claims 10-13, which as an ionic liquid is a phosphonium salt contains. Detergent according to claims 10-13, which as an ionic liquid is a 1,3-dialkylimidazolium salt contains. Detergent according to claims 10-13 containing as an ionic liquid a 1,2,3-trialkylimidazolium salt contains. Detergent according to claims 10 to 13, which contains an ionic liquid, which carries an alkanolamine function itself. Claimed is a detergent for deacidifying a gaseous fluid stream containing acid gases, characterized in that the detergent aa) an alkanolamine or a mixture of several alkanolamines, and bb) at least contains a hyperbranched polymer. a) the detergent may additionally contain water b) the detergent contains at least one hyperbranched polymer which is stable under the process conditions of gas scrubbing and the regeneration of the detergent. c) The hyperbranched polymer itself has, to a considerable extent, the ability to dissolve the acid gas component to be separated. Detergent according to claim 21, wherein the concentration on hyperbranched polymer, without mathematical consideration of water, between 0.1 and 90% by mass of hyperbranched Polymer, preferably between 10 and 85% by mass of hyperbranched Polymer, most suitably between 50 and 80 percent by mass hyperbranched polymer Detergent according to claim 22, which also contains water. Detergent according to claims 21 to 23 contains at least one hyperbranched polymer, the under the process conditions of gas scrubbing and regeneration of the detergent is stable. the detergent according to claims 21 to 24 contains at least one hyperbranched polymer, the soluble in the alkanolamine used at more than 10% by mass is and thereby forms a washing liquid whose viscosity less than 100 mPas at 25 ° C.