RU2478418C2 - Absorbing solution for cleaning gas flows of acid gases - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to extraction of carbon dioxide from gas flows by absorption. Proposed absorbing solution comprises active compound making 5-50% of total weight of absorbing solution. Said active compound contains bi- or tri-peptides or their salts, and amino acids, or their salts. Additionally, said solution contains alkanolamines, oligoamines, or piperazines.

EFFECT: higher absorption capacity, decreasing corrosion activity.

12 cl, 3 tbl

Description

The invention relates to the field of purification of gas streams from acid gases and can be used in the gas, oil and petrochemical industries in gas cleaning processes.

The problem of cleaning gas streams from acid gases, such as carbon dioxide and hydrogen sulfide, is relevant in connection with the increase in the economic activity of mankind and environmental pollution. Currently, the most common method of gas purification is the method of absorption of gas flows by various solutions of alkanolamines and other organic compounds.

A known method of cleaning gas streams according to European patent EP-A671200, where the removal of CO ₂ from gas streams is carried out at atmospheric pressure using solutions of metal salts of amino acids and piperazine. A solution is known to US Application US 2009/0199713 A1 regarding absorption media for the removal of acid gases based on at least one amine and at least one aminocarboxylic or aminosulfonic acid.

The closest to this invention is US patent No. 4094957 considering a solution of an absorbent containing alkaline salts of amino acids, sterically hindered amines and amino acids, such as N, N-dimethylglycine;

The disadvantages of the absorbents discussed in these patents are their high corrosion activity, relatively low absorption capacity (the absorption capacity is at the level of alkanolamines used in the industry and amounts to no more than 0.5 mol CO ₂ / mol of absorbent) and high energy capacities for the regeneration of absorbents. The use of organic compounds such as piperazine in absorbents is accompanied by its entrainment and, consequently, the expenditure coefficient of the absorbent increases. A distinctive feature of all the above patents is the presence in the chemical structure of the active substance of only one active amino group that reacts with an acid gas (carbon dioxide) molecule by the reaction:

in the case of primary or secondary amines, and by reaction:

in the case of tertiary amines.

The technical result, to which the claimed invention is directed, is to increase the absorption capacity of the absorbent, reduce the corrosion activity of the absorbent solution, which leads to a decrease in flow rates and improves the technical and economic parameters of the process.

The object of this invention is an absorbent solution consisting of an active composition and a medium for its dissolution. An absorbent solution can be used to clean gas streams from carbon dioxide and / or hydrogen sulfide and other acid gases. The absorbent solution contains an active composition, the concentration of which is from 5 to 50% of the total weight of the solution. The active composition is a mixture of at least two components of type A and B. Component A is a dipeptide, or tripeptide, or their sodium and / or potassium salts, while the molecule of component A contains at least one peptide bond in the structure:

The concentration of component A is from 0.5 to 99.5% of the total mass of the active composition.

Examples of components A can be dipeptides: glycine-alanine, glycine-dimethylglycine, glycine-arginine, lysine-lysine; tripeptides: glutamine-dimethylglycine-glycine, glycine-dimethylglycine-arginine, as well as their sodium or potassium salts. Used peptides can have both regular and non-regular structure.

The second component B of the active composition is amino acids and / or a mixture of amino acids or their salts. The concentration of component B is from 0.5 to 99.5% of the mass of the total weight of the active composition.

Examples of components B can be lysine, dimethylglycine, alanine, arginine, glutamine, glycine, and / or their sodium, and / or potassium, and / or cesium salts. Component B can be either a single amino acid or a mixture of amino acids and / or their salts. Amino acids may contain one or more chiral carbon atoms. The configuration of carbon atoms does not matter. Component B may contain not only pure enantiomers / diastereomers, but also racemic mixtures.

Addition of known acid gas absorbers, such as alkanolamines, to the absorbent solution, of the general formula [US 2008/0236390 A1]:

where R ₁ -R ₈ - can be the same and / or different and are hydrogen atoms and / or C ₂ -C ₅ alkyl groups, and M are alkali metal atoms;

and

;

;

piperazines of the general formula [WO 2009/156273 A1]:

where R ^a -R ^e - can be the same or different functional groups, such as - H, C ₁ -C ₅ ), Ph;

oligoamines of the general formula [WO 2009/156273 A1] ::

where R ₁ , R ₂ - can be either the same or different functional groups, such as - H, C ₁ -C ₅ , Ph; an = 1 to 10 and p = 1 to 10 (examples of this type of compound are spermine, spermidine, putrescine)

leads to an increase in the duration of stable operation of the absorbent solution, which also contributes to a decrease in the flow rate of the process.

The medium for dissolving the active composition may be water and / or other physical solvents, which, for example, may be cyclotetramethyl sulfone (sulfolane) or its derivatives, aliphatic acid amides (acetomorpholine, N-formylmorpholine), N-alkylated pyrrolidones and corresponding piperidones, such as N-methylpyrrolidone, propylene carbonate, methanol, dialkyl ethers of polyethylene glycols and mixtures thereof.

The active composition may be part of the absorbent solution in the form of an aqueous solution and / or solid substance, which dissolves in the medium of the absorbent solution.

In addition to solutions, this active composition can be included in the composition of ionic liquids or be applied to the membrane.

The absorbent solution may also include stabilizers, in particular antioxidants, such as those described in DE 10 2004 011 427, and corrosion inhibitors.

The present invention provides a new type of absorbent solution, comprising components containing dipeptides, tripeptides, tetrapeptides and oligopeptides, as well as the amino acids and / or their salts themselves, on the basis of which these peptides are obtained. The composition of the absorbent solution may include a salt of one amino acid or a mixture of salts of various amino acids. Preferred is the potassium or sodium salt of L-lysine as an amino acid having two amino groups.

The presence of two amino groups leads to an increase in the absorption capacity of the absorbent.

Figure 1 shows the kinetic absorption curves of carbon dioxide in an absorbent solution prepared according to method 2.3 and monoethanolamine.

The absorption capacity of an absorbing solution based on L-lysine (an absorbing solution prepared according to method 2.2) is at least 1 mol of CO ₂ per mole of absorbent material, which is almost 2 times higher than the known alkanolamines (monoethanolamine, methyldiethanamine, etc.), as well as and salts of amino acids (glycine, dimethylglycine, alanine, etc.).

Figure 2 shows the equilibrium curves of the degree of absorption of absorbent solutions depending on the partial pressure of carbon dioxide. For comparison, 30% aqueous solutions of monoethanolamine (MEA) and sodium glycinate (GN) were used.

Oligopeptides can be obtained by the following reaction:

The resulting oligopeptides, as well as amino acid salts, are capable of absorbing carbon dioxide [J. Org. Chem. 2006, 71, 8696-8705].

Oligopeptides are formed by heating amino acids or their salts. The resulting peptide compounds have a high molecular weight and, therefore, low volatility. It is also known that the formation of polymers by this reaction is impossible, therefore, the use of stable compounds not capable of further reactions contributes to the long-term stable operation of the absorbent solution. The decrease in the volatility of the components in the absorbent and the operation in a stable mode, as well as an increase in the absorption capacity, leads to a decrease in flow rates and improves the technical and economic performance of the process.

Figure 3 shows the kinetic curves for an absorbent solution prepared according to method 2.3., 30% aqueous solution of GN and 30% aqueous solution of MEA.

Absorbent solutions based on compounds having a peptide bond provide stable absorption of carbon dioxide at the level of known industrial absorbents (such as monoethanolamine (MEA)) for a long time. The rate of absorption of carbon dioxide by the considered absorbent solutions is higher in comparison with aqueous solutions of MEA.

The presence of oligopeptides in the absorbent solution leads to a decrease in the corrosivity of the solution, which improves the operational characteristics of the equipment.

Experiments confirming the possibility of implementing the claimed invention, but not limiting the possibility of its implementation.

Method 1

Composition 1.1

Glycine (10.25 g, Sigma) and dimethylglycine (14.4 g, Sigma) are heated in a porcelain cup with stirring in the temperature range from 80 to 200 ° C, until a homogeneous mass is obtained. After cooling, the resulting mass is treated with 0.1 N. NaOH solution, at the rate of 0.5 equivalent of NaOH per 1 equivalent of glycine, and then use this solution as component A of the active composition. The presence of the peptide bond was determined by ¹³ C and ¹ H NMR spectra, the formation of trimeric and dimeric structures using liquid chromatography mass spectrometry. Elemental analysis: Found (for glycine-dimethylglycine dipeptide): 39.56% (C); 6.09% (H); 15.38% (N); 12.62% (Na); 26.35% (O); Received: 40.4% (C); 5.97% (H); 16.9% (N); 9.41% (Na).

An equimolar amount of 0.1 N was pinned to a glycine solution (15.5 g, Sigma). NaOH solution. The solution was stirred for 6 hours and then the resulting solution was used as component B of the active composition.

Composition 1.2

A solution of sodium glycinate (100 ml) obtained by processing 10.25 g of glycine 0.1 N. equimolar sodium hydroxide solution and 100 ml of sodium dimethyl glycinate solution, also obtained by processing 14.4 g of dimethyl glycine 0.1 n. sodium hydroxide solution in equimolar ratio, evaporated at a temperature of 120 ° C with constant stirring until a thick mass is formed. The presence of a peptide bond in the resulting product was determined by ¹³ C and ¹ H NMR spectra. The resulting product was used further as component A of the active composition. An equimolar amount of 0.1 N was added to the L-lysine solution (17.4 g, Sigma). NaOH solution. The solution was stirred for 6 hours and then the resulting solution was used as component B of the active composition.

Composition 1.3

A solution of sodium glycinate (100 ml) obtained by processing 10.25 g of glycine 0.1 N. equimolar sodium hydroxide solution and 100 ml of sodium dimethyl glycinate solution, also obtained by processing 14.4 g of dimethyl glycine 0.1 n. sodium hydroxide solution in equimolar ratio, evaporated at a temperature of 120 ° C with constant stirring until a thick mass is formed. The presence of a peptide bond in the resulting product was determined by ¹³ C and ¹ H NMR spectra. The resulting product was used further as component A of the active composition.

An equimolar amount of 0.1 N was added to the L-lysine solution (17.4 g, Sigma). NaOH solution. The solution was stirred for 6 hours and then the resulting solution was used as component B of the active composition.

Composition 1.4

150 g of an aqueous solution of a mixture of sodium lysinate and sodium dimethyl glycinate obtained by processing 17.4 g of L-lysine and 14.4 g of dimethyl glycine 0.1 N NaOH solution in equimolar ratio, respectively, was heated for 15 minutes with constant stirring at a temperature of 100-120 ° C. The presence of the peptide bond is spectrally fixed by ¹ H and ¹³ C NMR methods. After that, the resulting solution is used as a mixture of components A and B of the active composition.

Composition 1.5

It is similar to composition 1.1, only 0.2 g of piperazine is added to the mixture of components A and B (the ratio of component B to piperazine is 1: 0.01).

Composition 1.6

Component A is similar to composition 1.1. To prepare component B, 7.73 g of glycine is used, treated equimolarly with 0.1 N. NaOH solution and then 10 g of monoethanolamine is added to the mixture of components A and B (the ratio of component B to monoethanolamine is 1: 1).

Composition 1.7

It is similar to composition 1.1, only 0.2 g of spermine is added to the mixture of components A and B (the ratio of component B to spermine is 1: 0.01).

Method 2

Composition 2.1

A solution of sodium glycinate (100 ml) obtained by processing 10.25 g of glycine 0.1 N. equimolar sodium hydroxide solution and 100 ml of sodium dimethyl glycinate solution, also obtained by processing 14.4 g of dimethyl glycine 0.1 n. sodium hydroxide solution in equimolar ratio, evaporated at a temperature of 120 ° C with constant stirring until a thick mass is formed. The presence of the peptide bond in the resulting product was determined by ¹³ C and ¹ H NMR spectra, the formation of trimeric and dimeric structures using liquid chromatography-mass spectrometry. The resulting product was used further as component A of the active composition.

An equimolar amount of 0.1 N was added to the L-lysine solution (17.4 g, Sigma). NaOH solution. The solution was stirred for 6 hours and then the resulting solution was used as component B of the active composition.

Composition 2.2

The composition was prepared according to method 2 only in the preparation of component A, instead of glycine, 23.69 g of phenylalanine was used, and instead of dimethylglycine, 19.88 g of L-lysine.

Method 2.1

The components of the active composition prepared according to method 1.1 are dissolved in water so that the mass of the absorbent solution is 150 g (i.e., the total content of the compounds constituting the active composition is 30% by weight of the total weight of the solution).

Method 2.2 Similar to method 2.1., Only the active composition was prepared according to method 1.2.

Method 2.3 Similar to method 2.1., Only the active composition was prepared according to method 1.3.

Method 2.4 Similar to method 2.1., Only the active composition was prepared according to method 1.4.

Method 2.5 Similar to method 2.1., Only the active composition was prepared according to method 1.5.

Method 2.6 It is similar to method 2.3., But instead of water, a mixture of water and methanol is used in a ratio of 10: 1.

Method 2.7 Similar to method 2.3., Only instead of water, a mixture of water and cyclotetramethyl sulfone in a ratio of 10: 1 is used.

Method 2.8 It is similar to method 2.3., Only instead of water a mixture of water and N-formylmorpholine is used, in a ratio of 10: 1.

Method 2.9. It is similar to method 2.3., Only instead of water a mixture of water and propylene carbonate is used, in a ratio of 10: 1.

Method 2.10. It is similar to method 2.3., But instead of water, a mixture of water and polyethylene glycol dimethyl ether in a ratio of 10: 1 is used.

Method 3

Composition 3.1.

150 g of an aqueous solution of a mixture of sodium lysinate and sodium dimethyl glycinate obtained by processing 17.4 g of L-lysine and 14.4 g of dimethyl glycine 0.1 N NaOH solution in equimolar ratio, respectively, was heated for 15 minutes with constant stirring at a temperature of 100-120 ° C. The presence of the peptide bond is detected spectrally by ¹ H and ¹³ C NMR, formation of trimeric and dimeric structures using liquid chromatography-mass spectrometry. After which the resulting solution is used as a mixture of components A and B of the active composition. Composition 3.2. The composition was prepared according to method 3, only when preparing the active composition used 23.69 g of phenylalanine and 19.88 g of L-lysine.

Composition 3.3.

The composition was prepared according to method 3, only in the preparation of the active composition used 15.91 gvalina and 19.88 g of L-lysine.

Preparation of an absorbent solution

Method 4

Solution 4.1 Active composition 1.1 is dissolved in water so that the mass of the absorbent solution is 100 g, while the total content of active compounds is 30% by weight of the total weight of the solution, and the mass of component A is 0.5% by weight of the weight of the active composition.

Solution 4.2. The solution is prepared similarly to solution 4.1., Only the active composition 1.2 is used.

Solution 4.3. The solution is prepared similarly to solution 4.1., Only active composition 1.3 is used.

Solution 4.4. The solution is prepared similarly to solution 4.1., Only active composition 1.4 is used.

Solution 4.5. The solution is prepared similarly to solution 4.1., Only active composition 1.5 is used.

Solution 4.6. The solution is prepared similarly to solution 4.1., Only active composition 1.6 is used.

Solution 4.7. The solution is prepared similarly to solution 4.1., Only active composition 2.1 is used.

Solution 4.8. The solution is prepared similarly to solution 4.1., Only active composition 2.2 is used.

Solution 4.9. The solution is prepared similarly to solution 4.1., Only active composition 3.1 is used.

Solution 4.10. The solution is prepared similarly to solution 4.1., Only the active composition 3.2 is used.

Solution 4.11. The solution is prepared similarly to solution 4.1., Only the active composition 3.3 is used.

Solution 4.12. The solution is prepared similarly to solution 4.1., Only monoethanolamine is used, instead of components A and B.

Solution 4.13. The solution is prepared similarly to solution 4.1., Only sodium glycinate is used, instead of components A and B

Method 5

Solution 5.1. The active composition 1.1 is dissolved in water so that the mass of the absorbent solution is 100 g, while the total content of the compounds of the active composition is 30% by weight of the total weight of the solution, and the mass of component A is 10 wt.% Of the weight of the active composition.

Solution 5.2.

The solution is prepared similarly to solution 5.1., Only active composition 1.2 is used.

Solution 5.3.

The solution is prepared similarly to solution 5.1., Only active composition 1.3 is used.

Solution 5.4.

The solution is prepared similarly to solution 5.1., Only active composition 1.4 is used.

Solution 5.5.

The solution is prepared similarly to solution 5.1., Only active composition 1.5 is used.

Solution 5.6.

The solution is prepared similarly to solution 5.1., Only active composition 1.6 is used.

Solution 5.7.

The solution is prepared similarly to solution 5.1., Only active composition 1.7 is used.

Solution 5.8.

The solution is prepared similarly to solution 5.1., Only active composition 2.1 is used.

Solution 5.9.

The solution is prepared similarly to solution 5.1., Only active composition 2.2 is used.

Solution 5.10.

The solution is prepared similarly to solution 5.1., Only active composition 2.3 is used.

Solution 5.11.

The solution is prepared similarly to solution 5.1., Only the active composition 2.4 is used.

Solution 5.12.

The solution is prepared similarly to solution 5.1., Only active composition 2.5 is used.

Solution 5.13.

The solution is prepared similarly to solution 5.1., Only the active composition 2.6 is used.

Solution 5.14.

The solution is prepared similarly to solution 5.1. active compound 2.7 is only used.

Solution 5.15.

The solution is prepared similarly to solution 5.1., Only active composition 2.8 is used.

Solution 5.16.

The solution is prepared similarly to solution 5.1., Only active composition 2.9 is used.

Solution 5.17.

The solution is prepared similarly to solution 5.1., Only the active composition 2.10 is used.

Solution 5.18.

The solution is prepared similarly to solution 5.1., Only active composition 3.1 is used.

Solution 5.19.

The solution is prepared similarly to solution 5.1., Only the active composition 3.2 is used.

Solution 5.20.

The solution is prepared similarly to solution 5.1., Only active composition 3.3 is used.

Method 6

Solution 6.1. The active composition 1.1 is dissolved in water so that the mass of the absorbent solution is 100 g, while the total content of the compounds of the active composition is 30% by weight of the total weight of the solution, and the mass of component A is 50 wt.% By weight of the active composition.

Solution 6.2.

The solution is prepared similarly to solution 6.1., Only the active composition 1.2 is used.

Solution 6.3.

The solution is prepared similarly to solution 6.1., Only active composition 1.3 is used.

Solution 6.4.

The solution is prepared similarly to solution 6.1., Only active composition 1.4 is used.

Solution 6.5.

The solution is prepared similarly to solution 6.1., Only active composition 1.5 is used.

Solution 6.6.

The solution is prepared similarly to solution 6.1., Only active composition 1.6 is used.

Solution 6.7.

The solution is prepared similarly to solution 6.1., Only active composition 2.1 is used.

Solution 6.8.

The solution is prepared similarly to solution 6.1., Only active composition 2.2 is used.

Solution 6.9.

The solution is prepared similarly to solution 6.1., Only active composition 3.1 is used.

Solution 6.10.

The solution is prepared similarly to solution 6.1., Only the active composition 3.2 is used.

Solution 6.11.

The solution is prepared similarly to solution 6.1., Only the active composition 3.3 is used.

Method 7

Solution 7.1. The active composition 1.1 is dissolved in water so that the mass of the absorbent solution is 100 g, while the total content of the compounds of the active composition is 20% by weight of the total weight of the solution, and the mass of component A is 0.5% by weight of the weight of the active composition.

Solution 7.2.

The solution is prepared similarly to solution 7.1., Only the active composition 1.2 is used.

Solution 7.3.

The solution is prepared similarly to solution 7.1., Only active composition 1.3 is used.

Solution 7.4.

The solution is prepared similarly to solution 7.1., Only active composition 1.4 is used.

Solution 7.5.

The solution is prepared similarly to solution 7.1., Only active composition 1.5 is used.

Solution 7.6.

The solution is prepared similarly to solution 7.1., Only active composition 1.6 is used.

Solution 7.7

The solution is prepared similarly to solution 7.1., Only active composition 2.1 is used.

Solution 7.8.

The solution is prepared similarly to solution 7.1., Only active composition 2.2 is used.

Solution 7.9.

The solution is prepared similarly to solution 7.1., Only active composition 3.1 is used.

Solution 7.10.

The solution is prepared similarly to solution 7.1., Only the active composition 3.2 is used.

Solution 7.11.

The solution is prepared similarly to solution 7.1., Only active composition 3.3 is used.

Solution 7.12.

The solution is prepared similarly to solution 7.1., Only monoethanolamine is used, instead of components A and B.

Solution 7.13.

The solution is prepared similarly to solution 7.1. only sodium glycinate is used, instead of components A and B.

Method 8

Solution 8.1 The active composition 1.1 is dissolved in water so that the mass of the absorbent solution is 100 g, while the total content of the compounds of the active composition is 20% by weight of the total weight of the solution, and the mass of component A is 10% by weight of the weight of the active composition.

Solution 8.2.

The solution is prepared similarly to solution 8.1., Only active composition 1.2 is used.

Solution 8.3.

The solution is prepared similarly to solution 8.1., Only active composition 1.3 is used.

Solution 8.4.

The solution is prepared similarly to solution 8.1., Only active composition 1.4 is used.

Solution 8.5.

The solution is prepared similarly to solution 8.1., Only active composition 1.5 is used.

Solution 8.6.

The solution is prepared similarly to solution 8.1., Only active composition 1.6 is used.

Solution 8.7.

The solution is prepared similarly to solution 8.1., Only active composition 2.1 is used.

Solution 8.8.

The solution is prepared similarly to solution 8.1., Only active composition 2.2 is used.

Solution 8.9.

The solution is prepared similarly to solution 8.1., Only active composition 3.1 is used.

Solution 8.10.

The solution is prepared similarly to solution 8.1., Only the active composition 3.2 is used.

Solution 8.11.

The solution is prepared similarly to solution 8.1., Only active composition 3.3 is used.

Method 9

Solution 9.1 The active composition 1.1 is dissolved in water so that the mass of the absorbent solution is 100 g, while the total content of the compounds of the active composition is 20% by weight of the total weight of the solution, and the mass of component A is 50% by weight of the weight of the active composition.

Solution 9.2.

The solution is prepared similarly to solution 9.1., Only the active composition 1.2 is used.

Solution 9.3.

The solution is prepared similarly to solution 9.1. active compound 1.3 is only used.

Solution 9.4.

The solution is prepared similarly to solution 9.1., Only active composition 1.4 is used.

Solution 9.5.

The solution is prepared similarly to solution 9.1., Only active composition 1.5 is used.

Solution 9.6.

The solution is prepared similarly to solution 9.1., Only the active composition 1.6 is used.

Solution 9.7.

The solution is prepared similarly to solution 9.1., Only the active composition 2.1 is used.

Solution 9.8.

The solution is prepared similarly to solution 9.1., Only the active composition 2.2 is used.

Solution 9.9.

The solution is prepared similarly to solution 9.1., Only the active composition 3.1 is used.

Solution 9.10.

The solution is prepared similarly to solution 9.1., Only the active composition 3.2 is used.

Solution 9.11.

The solution is prepared similarly to solution 9.1., Only the active composition 3.3 is used.

Method 10

Solution 10.1 Active composition 1.1 is dissolved in water so that the mass of the absorbent solution is 100 g, while the total content of the compounds of the active composition is 10% by weight of the total weight of the solution, and the mass of component A is 0.5% by weight of the weight of the active composition.

Solution 10.2.

The solution is prepared similarly to solution 10.1., Only the active composition 1.2 is used.

Solution 10.3.

The solution is prepared similarly to solution 10.1., Only active composition 1.3 is used.

Solution 10.4.

The solution is prepared similarly to solution 10.1., Only active composition 1.4 is used.

Solution 10.5.

The solution is prepared similarly to solution 10.1., Only active composition 1.5 is used.

Solution 10.6.

The solution is prepared similarly to solution 10.1., Only active composition 1.6 is used.

Solution 10.7.

The solution is prepared similarly to solution 10.1., Only active composition 2.1 is used.

Solution 10.8.

The solution is prepared similarly to solution 10.1., Only active composition 2.2 is used.

Solution 10.9.

The solution is prepared similarly to solution 10.1., Only active composition 3.1 is used.

Solution 10.10.

The solution is prepared similarly to solution 10.1., Only the active composition 3.2 is used.

Solution 10.11.

The solution is prepared similarly to solution 10.1., Only the active composition 3.3 is used.

Solution 10.12.

The solution is prepared similarly to solution 10.1., Only monoethanolamine is used, instead of components A and B.

Solution 10.13.

The solution is prepared similarly to solution 10.1., Only sodium glycinate is used, instead of components A and B.

Method 11

Solution 11.1. The active composition 1.1 is dissolved in water so that the mass of the absorbent solution is 100 g, while the total content of the compounds of the active composition is 10% by weight of the total weight of the solution, and the mass of component A is 10 wt.% Of the weight of the active composition.

Solution 11.2.

The solution is prepared similarly to solution 11.1., Only the active composition 1.2 is used.

Solution 11.3.

The solution is prepared similarly to solution 11.1., Only the active composition 1.3 is used.

Solution 11.4.

The solution is prepared similarly to solution 11.1., Only the active composition 1.4 is used.

Solution 11.5.

The solution is prepared similarly to solution 11.1., Only active composition 1.5 is used.

Solution 11.6.

The solution is prepared similarly to solution 11.1., Only the active composition 1.6 is used.

Solution 11.7.

The solution is prepared similarly to solution 11.1., Only the active composition 2.1 is used.

Solution 11.8.

The solution is prepared similarly to solution 11.1., Only the active composition 2.2 is used.

Solution 11.9.

The solution is prepared similarly to solution 11.1., Only the active composition 3.1 is used.

Solution 11.10.

The solution is prepared similarly to solution 11.1., Only the active composition 3.2 is used.

Solution 11.11.

The solution is prepared similarly to solution 11.1., Only the active composition 3.3 is used.

Method 12

Solution 12.1. The active composition 1.1 is dissolved in water so that the mass of the absorbent solution is 100 g, while the total content of the compounds of the active composition is 10% by mass of the total weight of the solution, and the mass of component A is 50 wt.% Of the weight of the active composition.

Solution 12.2.

The solution is prepared similarly to solution 9.1., Only the active composition 1.2 is used.

Solution 12.3.

The solution is prepared similarly to solution 5.1., Only active composition 1.3 is used.

Solution 12.4.

The solution is prepared similarly to solution 5.1., Only active composition 1.4 is used.

Solution 12.5.

The solution is prepared similarly to solution 5.1., Only active composition 1.5 is used.

Solution 12.6.

The solution is prepared similarly to solution 5.1., Only active composition 1.6 is used.

Solution 12.7.

The solution is prepared similarly to solution 5.1., Only active composition 2.1 is used.

Solution 12.8.

The solution is prepared similarly to solution 5.1., Only active composition 2.2 is used.

Solution 12.9.

The solution is prepared similarly to solution 5.1., Only active composition 3.1 is used.

Solution 12.10.

The solution is prepared similarly to solution 5.1., Only the active composition 3.2 is used.

Solution 12.11.

The solution is prepared similarly to solution 5.1., Only active composition 3.3 is used.

Experiment 1

In a bubble-type reactor equipped with a “jacket”, 100 ml of solution 4.1. Was loaded, and at a temperature of 35 ° C in the “jacket” of the reactor, and a gas-air mixture was passed through the solution for 1 hour at a speed of 4 l / h containing dioxide carbon.

The gas concentration in the inlet and outlet stream was determined using a Crystallux 2000M chromatograph. The concentration of acid gas in the solution was determined by volumetric method.

Experiments 2-111 were carried out similarly to experiment 1, only solutions 4.2-4.13, 5.1-5.20 were used; 6.1-6.11; 7.1-7.13; 8.1-8.11; 9.1-9.11; 10.1-10.13; 11.1-11.11 and 12.1-12.11.

Experiments 103-214 are similar to experiments 1-111 only a gas-air mixture contained hydrogen sulfide.

After saturation with acid gases, all solutions were regenerated by heating at a temperature of 115 ° С for 20 min. Then they were used for re-absorption. One cycle of the process consists of 1 absorption and 1 regeneration of the solution. The degree of purification was calculated by the formula:

A = (1 - ((concentration of acid gas in the outgoing gas-air mixture) / (concentration of acid gas in the initial gas-air mixture)))

The results of the experiments are shown in tables 1 and 2.

Table 1 The degree of purification of the gas-air mixture from carbon dioxide. Number of cycles 100 Experiment number The concentration of acid gas, vol.% twenty 5 0.5 one. 0.45 0.42 0.4 2. 0.6 0.58 0.5 3. 0.5 0.48 0.44 four. 0.52 0.44 0.4 5. 0.48 0.42 0.4 6. 0.48 0.44 0.4 7. 0.46 0.42 0.38 8. 0.58 0.53 0.5 9. 0.5 0.42 0.38 10. 0.57 0.52 0.5 eleven. 0.46 0.42 0.40 12. 0.37 0.34 0.33 13. 0.56 0.5 0.5 fourteen. 0.48 0.44 0.40 fifteen. 0.6 0.5 0.46 16. 0.46 0.44 0.42 17. 0.48 0.46 0.42 eighteen. 0.62 0.54 0.5 19. 0.62 0.6 0.52 twenty. 0.6 0.6 0.51 21. 0.62 0.58 0.52 22. 0.6 0.58 0.56 23. 0.45 0.4 0.36 24. 0.62 0.52 0.51 25. 0.45 0.42 0.4 26. 0.6 0.51 0.5 27. 0.48 0.44 0.40 28. 0.62 0.58 0.5 29. 0.48 0.44 0.4 thirty. 0.5 0.44 0.4 31. 0.5 0.48 0.46 32. 0.5 0.46 0.44 33. 0.58 0.54 0.5 34. 0.56 0.5 0.46 35. 0.52 0.5 0.45 36. 0.54 0.54 0.5 37. 0.6 0.5 0.5 38. 0.6 0.5 0.5 39. 0.6 0.5 0.48 40. 0.5 0.3 0.21 41. 0.5 0.32 0.25 42. 0.48 0.4 0.38 43. 0.5 0.5 0.42 44. 0.52 0.5 0.38 45. 0.46 0.42 0.36 46. 0.52 0.5 0.32 47. 0.38 0.35 0.32 48. 0.56 0.5 0.42 49. 0.52 0.4 0.3 fifty. 0.5 0.48 0.32 51. 0.52 0.4 0.32 52. 0.52 0.52 0.31 53. 0.54 0.52 0.45 54. 0.56 0.4 0.32 55. 0.58 0.4 0.34 56. 0.54 0.4 0.3 57. 0.42 0.38 0.28 58. 0.46 0.4 0.4 59. 0.48 0.42 0.32 60. 0.5 0.48 0.42 61. 0.5 0.46 0.42 62. 0.52 0.46 0.4 63. 0.48 0.39 0.34 64. 0.42 0.39 0.32 65. 0.52 0.42 0.36 66. 0.56 0.48 0.34 67. 0.54 0.52 0.32 68. 0.54 0.5 0.42 69. 0.52 0.5 0.32 70. 0.51 0.41 0.36 71. 0.46 0.4 0.32 72. 0.46 0.42 0.31 73. 0.44 0.42 0.3 74. 0.48 0.42 0.4 75. 0.52 0.48 0.4 76. 0.58 0.46 0.4 77. 0.58 0.42 0.38 78. 0.56 0.52 0.36 79. 0.6 0.52 0.38 80. 0.6 0.41 0.32 81. 0.48 0.4 0.38 82. 0.37 0.35 0.34 83. 0.52 0.5 0.38 84. 0.44 0.42 0.36 85. 0.51 0.5 0.32 86. 0.5 0.42 0.3 87. 0.56 0.5 0.42 88. 0.5 0.4 0.3 89. 0.46 0.48 0.32 90. 0.52 0.4 0.32 91. 0.52 0.53 0.31 92. 0.54 0.52 0.45 93. 0.56 0.4 0.32 94. 0.58 0.4 0.34 95. 0.54 0.4 0.3 96. 0.443 0.38 0.28 97. 0.46 0.4 0.3 98. 0.48 0.42 0.32 99. 0.5 0.48 0.42 one hundred. 0.48 0.46 0.42 101. 0.52 0.46 0.42 102. 0.48 0.39 0.34 103. 0.52 0.5 0.38 104. 0.44 0.42 0.36 105. 0.51 0.5 0.32 106. 0.5 0.42 0.3 107. 0.56 0.5 0.42 108. 0.5 0.4 0.3 109. 0.46 0.48 0.32 110. 0.52 0.4 0.32 111. 0.52 0.53 0.31

table 2 The degree of gas purification from hydrogen sulfide and other gases The number of cycles 50 Experiment number The concentration of acid gas, vol.% 1,0 0.5 0.1 112. 0.45 0.42 0.4 113. 0.6 0.58 0.5 114. 0.5 0.48 0.44 115. 0.52 0.44 0.4 116. 0.48 0.42 0.4 117. 0.48 0.44 0.4 118. 0.46 0.42 0.38 119. 0.58 0.53 0.5 120. 0.5 0.42 0.38 121. 0.57 0.52 0.5 122. 0.46 0.42 0.40 123. 0.3 0.35 0.33 124. 0.56 0.5 0.5 125. 0.48 0.44 0.40 126. 0.6 0.5 0.46 127. 0.46 0.44 0.42 128. 0.48 0.46 0.42 129. 0.62 0.54 0.5 130. 0.62 0.6 0.52 131. 0.6 0.6 0.51 132. 0.62 0.58 0.52 133. 0.6 0.58 0.56 134. 0.45 0.4 0.36 135. 0.62 0.52 0.51 136. 0.45 0.42 0.4 137. 0.6 0.51 0.5 138. 0.48 0.44 0.40 139. 0.62 0.58 0.5 140. 0.48 0.44 0.4 141. 0.5 0.44 0.4 142. 0.5 0.48 0.46 143. 0.5 0.46 0.44 144. 0.58 0.54 0.5 145. 0.56 0.5 0.46 146. 0.52 0.5 0.45 147. 0.54 0.54 0.5 148. 0.6 0.5 0.5 149. 0.6 0.5 0.5 150. 0.6 0.5 0.48 151. 0.5 0.3 0.21 152. 0.5 0.32 0.25 153. 0.48 0.4 0.38 154. 0.5 0.5 0.42 155. 0.52 0.5 0.38 156. 0.46 0.42 0.36 157. 0.52 0.5 0.32 158. 0.37 0.39 0.32 159. 0.56 0.5 0.42 160. 0.52 0.4 0.3 161. 0.5 0.48 0.32 162. 0.52 0.4 0.32 163. 0.52 0.52 0.31 164. 0.54 0.52 0.45 165. 0.56 0.4 0.32 166. 0.58 0.4 0.34 167. 0.54 0.4 0.3 168. 0.42 0.38 0.28 169. 0.46 0.4 0.4 170. 0.48 0.42 0.32 171. 0.5 0.48 0.42 172. 0.5 0.46 0.42 173. 0.52 0.46 0.4 174. 0.48 0.39 0.34 175. 0.42 0.39 0.32 176. 0.52 0.42 0.36 177. 0.56 0.48 0.34 178. 0.54 0.52 0.32 179. 0.54 0.5 0.42 180. 0.52 0.5 0.32 181. 0.51 0.41 0.36 182. 0.46 0.4 0.32 183. 0.38 0.37 0.31 184. 0.44 0.42 0.3 185. 0.48 0.42 0.4 186. 0.52 0.48 0.4 187. 0.58 0.46 0.4 188. 0.58 0.42 0.38 189. 0.56 0.52 0.36 190. 0.6 0.52 0.38 191. 0.6 0.41 0.32 192. 0.48 0.4 0.38 193. 0.5 0.5 0.42 194. 0.52 0.5 0.38 195. 0.44 0.42 0.36 196. 0.51 0.5 0.32 197. 0.5 0.42 0.3 198. 0.56 0.5 0.42 199. 0.5 0.4 0.3 200. 0.46 0.48 0.32 201. 0.52 0.4 0.32 202. 0.52 0.53 0.31 203. 0.54 0.52 0.45 204. 0.56 0.4 0.32 205. 0.58 0.4 0.34 206. 0.54 0.4 0.3 207. 0.443 0.38 0.28 208. 0.46 0.4 0.3 209. 0.48 0.42 0.32 210. 0.5 0.48 0.42 211. 0.48 0.46 0.42 212. 0.52 0.46 0.42 213. 0.48 0.39 0.34 214. 0.42 0.39 0.32

The experiments to determine the corrosivity of the absorbent solution were carried out according to the method of GOST 9.908-85. The test results are shown in Table 3.

Table 3 The corrosion rate of carbon steel 12X18H10T in solutions of various absorbers. Absorber Oxygen content,% Temperature ° C The corrosion rate, g / m ² * h IEA * 0.4 one hundred 0.299 Absorbent solution prepared according to method 2.3 0.4 one hundred 0.009

The invention allows to remove not only carbon dioxide from the gas streams, but also other gases, in particular H ₂ S, SO ₂ , CS ₂ , HCN, COS, NO ₂ , HCl, disulfides or mercaptans.

The partial pressure of acid gases in the cleaned gas streams is at least 0.05 kPa.

The invention can be used for cleaning gas flows of all types. Gas streams that include acidic gases are the most preferred streams, for example natural gas streams, gas furnace emissions, coal gasification gases, recycle gases, underground explosive gases, and indoor air.

The invention can be used to purify waste liquids, especially those that are not miscible with an absorbent solution, such as liquefied petroleum gas or liquefied natural gas.

An absorbent solution can be used to treat hydrocarbon streams. In this case, for example, hydrocarbons such as C ₁ -C ₁₁ aliphatic hydrocarbons (methane) or aromatics (benzene, toluene or xylene) may be present in the stream.

Processed gas streams can be obtained due to:

- oxidation of organic compounds, for example fuel gas;

- decomposition and storage of waste, which includes organic substances;

- decomposition of organic substances by various bacteria;

- accumulation of acid gases in indoor air.

Devices for conducting the process of cleaning gas flows by the presented absorbent solution include at least one absorption column, for example, a screed or packed column, and / or other types of contact devices, for example, a membrane reactor, radial inlet scrubber, non-nozzle scrubber, scrubber Venturi, rotary spray scrubber.

It is preferable to use an absorbent solution in countercurrent with a gas stream. In this case, the gas stream enters from the bottom of the column, and the absorption solution from the top of the column.

Suitable materials for processing gas streams with an absorbent solution in absorbers are stainless steel materials, as well as materials based on plastics such as polyolefins and / or polytetrafluoroethylene, or absorbers in which the interior is fully or partially covered with plastic.

The absorption temperature is from 20 to 100 ° C.

Desorption of a saturated absorbent solution, i.e. the solution that has passed the absorption device in countercurrent and / or forward flow with the gas to be cleaned is carried out:

1) by heating, for example from 70 to 150 ° C,

2) by extension,

3) inert flow distillation

or a combination of these methods, as well as

4) exposure to microwave radiation.

Claims (12)

1. An absorbent solution for cleaning gas streams from acid gases, consisting of an active composition and a medium for its dissolution, where the active composition is a mixture of at least two components of type A and B, and its concentration is from 5 to 50% of the total the weight of the solution, while component A is a di- or tri-pepdide or their sodium and / or potassium salts, the molecule of component A contains at least one peptide bond in the structure:

and the concentration of component A is from 0.5 to 99.5% of the total mass of the active composition,
component B is an amino acid or a mixture of amino acids or their salts,
and the concentration of component B is from 0.5 to 99.5 wt.% of the total weight of the active composition. 2. The absorbent solution according to claim 1, characterized in that the active composition additionally contains alkanolamines of the General formula:

where R ₁ -R ₈ can be the same and / or different and are hydrogen atoms and / or C ₂ -C ₅ alkyl groups, and M are alkali metal atoms. 3. The absorbent solution according to claim 1, characterized in that the active composition further comprises oligoamines of the general formula:

where R ₁ , R ₂ - can be either the same or different functional groups, such as - H, C ₁ -C ₅ , Ph; an = 1 to 10 and p = 1 to 10, for example, spermine, spermidine, putrescine. 4. The absorbent solution according to claim 1, characterized in that the mixture of the active composition further comprises piperazines of the general formula:

where R ^a -R ^e can be the same or different functional groups, such as - H, C ₁ -C ₅ , Ph, for example piperazine, N-methylpiperazine, N-phenylpiperazine. 5. The absorbent solution according to claim 1, characterized in that the mixture of the active composition additionally contains alkanolamines of the General formula:

6. The absorbent solution according to claim 1, characterized in that the medium for dissolving the active composition is water. 7. The absorbent solution according to claim 1, characterized in that the medium for dissolving the active composition is a mixture of water with physical solvents. 8. The absorbent solution according to claim 7, characterized in that the physical solvent is cyclotetramethyl sulfone (sulfolane) or its derivatives. 9. The absorbent solution according to claim 7, characterized in that the physical solvent are amides of aliphatic acids (acetomorpholine, N-formylmorpholine), N-alkylated pyrrolidones and the corresponding piperidones. 10. The absorbent solution according to claim 7, characterized in that the physical solvent is propylene carbonate. 11. The absorbent solution according to claim 7, characterized in that the physical solvent is methanol. 12. The absorbent solution according to claim 7, characterized in that the physical solvent is dialkyl ethers of polyethylene glycols and mixtures thereof.

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