A deep eutectic solvent taking pyridine derivative as hydrogen bond acceptor, and a preparation method and application thereof

Abstract

The application discloses a pyridine derivative-based deep eutectic solvent and a preparation method and application thereof. The deep eutectic solvent is prepared from a pyridine derivative as a hydrogen bond acceptor and a polyhydric alcohol or polyhydric phenol as a hydrogen bond donor. The preparation method comprises the following steps: mixing the pyridine derivative and the hydrogen bond donor at a molar ratio of 1:0.5-6, stirring until uniform at 60-120 DEG C, and then drying under vacuum at 60-120 DEG C and cooling to room temperature to obtain the deep eutectic solvent. The pyridine derivative-based deep eutectic solvent prepared by the application has hydrogen bond interaction between alcohol hydroxyl and phenolic hydroxyl groups and ammonia molecules, which is beneficial to efficient absorption of ammonia. The ammonia can be desorbed and regenerated by simple pressure reduction and temperature rising operation. The pyridine derivative-based deep eutectic solvent has the characteristics of easy synthesis, easy regeneration, good stability, high ammonia absorption capacity and the like, and has a good application prospect in ammonia separation and storage.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ammonia capture, and particularly relates to a low eutectic solvent composed of pyridine derivatives as hydrogen bond acceptors and polyols and polyphenols as hydrogen bond donors, and application thereof in efficient and reversible capture of ammonia. BACKGROUND

[0002] Ammonia is a typical gaseous pollutant with irritating odor and slight toxicity, and is one of the main causes of haze formation in the atmosphere. Thanks to the Haber-Bosch ammonia synthesis method, ammonia can be industrially produced and widely used as a raw material for the synthesis of industrial products. Low-concentration ammonia can irritate the human eye and moist skin, and if inhaled by the human body, can burn the skin and the mucosa of the respiratory organs, and even cause lung swelling, leading to death. Recent studies have found that in the field of sustainable ammonia synthesis and conversion, ammonia can be used as an energy or hydrogen carrier, which has a bright application prospect. However, a large amount of ammonia-containing waste gas is generated in the process of industrial production or ammonia synthesis, and the direct emission of these waste gases into the air will cause a series of environmental problems and seriously endanger human health. Therefore, the storage, separation and recovery of ammonia, the control of environmental pollution and the rational use of resources are of great significance.

[0003] At present, the purification and recovery of ammonia-containing tail gas in industry mainly adopts water washing method and acid washing method. The water washing method is a physical absorption method, which uses soft water as absorbent to absorb ammonia in industrial tail gas. This method is mature in technology and widely used, but it cannot realize the separation of ammonia in industrial tail gas, and after absorbing ammonia, water can only obtain ammonia water with low concentration. In order to realize the regeneration of absorbent, high energy consumption is required. The acid washing method utilizes the alkaline property of ammonia, and makes ammonia react with the aqueous solution of acid. The acid used has very strong corrosive property, which can cause corrosion to the equipment and reduce the service life of the equipment. The acid and ammonia gas will undergo an irreversible reaction, making the ammonia recovery process very difficult. Therefore, in the past ten years, people have been committed to developing a new type of adsorbent with high capacity, low cost, good stability and reversibility, which can be used to remove and recover ammonia in ammonia-containing waste gas, which is of great significance in the treatment and recovery of ammonia-containing waste gas.

[0004] As a new material for gas absorption, ionic liquid has been applied in the field of ammonia absorption and separation in recent years due to its low vapor pressure, good solubility, adjustable structure and properties, and other characteristics, and has shown good ammonia absorption performance. However, ionic liquids have the characteristics of complex synthesis process, high price, difficulty in biodegradation, and even toxicity, which limits their application in actual industry.

[0005] Deep eutectic solvents (DESs), as an analogue of ionic liquids, have similar excellent physicochemical properties to ionic liquids and can effectively make up for the shortcomings of ionic liquids. The synthesis process is simple, raw materials are abundant and easy to obtain, the product purity is high, and it is easy to scale up. It has great potential in the field of gas separation and purification technology. A large number of literatures have reported that deep eutectic solvents can be used as absorbents for the absorption of CO2, SO2, H2S and other acidic gases (Trivedi et al., Green Chem. 2016, 18, 2834-2842; Yang et al., Phys. Chem. Chem. Phys. 2018, 20, 15168-15173; Shi et al., Sep. Purif. Technol. 2021, 276, 119357). In addition, some researchers have also done some research on the absorption of basic ammonia gas in deep eutectic solvents. Li et al. (Li et al., ChemSusChem 2017, 10, 3368-3377) first reported a hybrid deep eutectic solvent with a hydrogen-bonded supramolecular network structure. They used choline chloride as a hydrogen bond acceptor and phenolic compounds as a hydrogen bond donor to realize efficient absorption of ammonia gas by using the hydrogen bond interaction between hydroxyl and ammonia gas. Subsequently, a series of binary deep eutectic solvents (such as ammonium thiocyanate / glycerol, triazole / glycerol, imidazole / resorcinol, etc.) and ternary deep eutectic solvents (such as choline chloride / phenol / ethylene glycol, choline chloride / azole / ethylene glycol, ethanolamine hydrochloride / resorcinol / glycerol, etc.) were synthesized and used for ammonia storage and separation (Deng et al., Chem. Eng. J. 2018, 358, 936-943; Deng et al., New J. Chem. 2019, 43, 11636-11642; Luo et al., Chem. Eng. J. 2021, 416, 129114; Zhong et al., ACS Sustainable Chem. Eng. 2019, 7, 3258-3266, Zhong et al., ACS Sustainable Chem. Eng. 2019, 7, 14170; Luo et al., Sep. Purif. Technol. 2021, 260, 118240).In addition, there are also natural eutectic solvents (such as choline chloride / xylitol, glycolic acid / xylitol, etc.) and metal eutectic solvents (such as magnesium chloride / resorcinol / ethylene glycol, lithium chloride / ethylene glycol, etc.) as ammonia absorbents (Li et al., J. Mol. Liq. 2020, 317, 113992; Liu et al., Ind. Eng. Chem. Res. 2021, 60, 11600-11610; Sun et al., Int. J. Hydrogen Energy 2022, 47, 16121-16131; Li et al., Sep. Purif. Technol. 2021, 279, 119763).

[0006] At present, the hydrogen bond acceptor species used for synthesizing eutectic solvents are mainly quaternary ammonium salts, amines, azole compounds and metal chlorides. Finding new hydrogen bond acceptor species to prepare new eutectic solvents has important guiding significance for developing new ammonia storage and separation materials. SUMMARY

[0007] The purpose of the present application is to provide a eutectic solvent with pyridine derivatives as hydrogen bond acceptors and its preparation method and application, to provide new hydrogen bond acceptor species to prepare new eutectic solvents, and to solve the problem of irreversible reaction in the prior art by using the eutectic solvent as an absorbent to interact with ammonia molecules through hydrogen bonds between phenolic hydroxyl groups and alcoholic hydroxyl groups, so as to realize the desorption and regeneration of ammonia.

[0008] To achieve the above-mentioned purpose, the present application provides a eutectic solvent composed of pyridine derivatives as hydrogen bond acceptors and hydrogen bond donors.

[0009] Preferably, the pyridine derivative is one of 2-aminopyridine, 3-aminopyridine, 2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine, 2-acetylpyridine, 2-aminomethylpyridine; the hydrogen bond donor is a polyol or a polyphenol; the polyol is one of glycerol, ethylene glycol, 1,4-butanediol, pentaerythritol, xylitol, sorbitol; the polyphenol is one of resorcinol, catechol, hydroquinone, pyrogallol, m- pyrogallol.

[0010] Preferably, the molar ratio of the pyridine derivative to the hydrogen bond donor is 1:0.5-6.

[0011] The present application provides a preparation method of a eutectic solvent with pyridine derivatives as hydrogen bond acceptors, comprising the following steps: mixing pyridine derivatives and hydrogen bond donors at a molar ratio of 1:0.5-6, stirring uniformly at 60-120℃, then drying under vacuum at 60-120℃, and cooling to room temperature to obtain the eutectic solvent.

[0012] Preferably, the pyridine derivative is one of 2-aminopyridine, 3-aminopyridine, 2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine, 2-acetylpyridine, 2-aminomethylpyridine.

[0013] Preferably, the hydrogen bond donor is a polyol or a polyphenol.

[0014] Preferably, the polyol is one of glycerol, ethylene glycol, 1,4-butanediol, pentaerythritol, xylitol, sorbitol; and the polyphenol is one of m-dihydroxybenzene, o-dihydroxybenzene, p-dihydroxybenzene, benzene-1,3,5-triol, benzene-1,3,2-triol.

[0015] Preferably, the regeneration temperature is set to 40-100 DEG C, and the regeneration pressure is set to 0.01-0.1 MPa, so that the eutectic solvent is regenerated in circulation.

[0016] The application provides a use of a pyridine derivative-based eutectic solvent as a hydrogen bond acceptor, for absorbing and capturing ammonia.

[0017] Preferably, the temperature for absorbing ammonia by the eutectic solvent is set to 0-80 DEG C, and the absorption pressure is set to 0.01-0.1 MPa.

[0018] Compared with the prior art, the application has the following beneficial effects:

[0019] Currently, eutectic solvents are mostly composed of quaternary ammonium salts, quaternary phosphonium salts, azole compounds and metal chlorides as hydrogen bond acceptors, while the application proposes a stable eutectic solvent composed of pyridine derivatives as hydrogen bond acceptors and polyols and weakly acidic polyphenols as hydrogen bond donors, thus expanding the types of eutectic solvents.

[0020] The pyridine derivative-based eutectic solvent prepared in the application has abundant raw materials and simple synthesis, can form strong hydrogen bond interactions between the multiple active sites on alcohol hydroxyl groups and phenolic hydroxyl groups and ammonia, and realizes efficient and reversible absorption of ammonia. The simple operation of heating and reducing pressure can conveniently and effectively realize desorption of ammonia in the solvent, has good recycling property, and has good application prospect in the field of ammonia purification and separation.

[0021] The eutectic solvent prepared in the application provides abundant active sites for ammonia absorption by alcohol hydroxyl groups and weakly acidic phenolic hydroxyl groups in the eutectic solvent, can form hydrogen bond interactions between the active sites and ammonia, is suitable for capturing ammonia in tail gas discharged in the production process of ammonia industry and chemical products, and can realize selective absorption of ammonia.

[0022] The eutectic solvent has the characteristics of large ammonia gas absorption capacity, good stability, multiple recycling and the like, the synthesis raw material is cheap and easy to obtain, the synthesis method is simple, and the eutectic solvent is beneficial to large-scale production, and has potential application prospects in the absorption and storage of industrial ammonia gas. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is an ammonia gas absorption kinetics curve of different proportions of 2-aminopyridine / resorcinol eutectic solvents prepared by the present application;

[0024] Figure 2 is a thermogravimetric analysis result graph of 2-aminopyridine / resorcinol eutectic solvents prepared by the present application;

[0025] Figure 3 is a differential scanning calorimetry curve graph of 2-aminopyridine / resorcinol eutectic solvents prepared by the present application;

[0026] Figure 4 is a 5-cycle absorption result graph of 2-aminopyridine / resorcinol eutectic solvents prepared by the present application. DETAILED DESCRIPTION

[0027] The present application is further described below in conjunction with specific examples, but the present application is not limited in any way by the examples.

[0028] In the following examples, the instruments, reagents, materials and the like involved, if not specifically stated, are conventional instruments, reagents, materials and the like in the prior art, which can be obtained through regular commercial channels. In the following examples, the experimental methods, detection methods and the like involved, if not specifically stated, are conventional experimental methods, detection methods and the like in the prior art.

[0029] The present application provides a pyridine derivative-based eutectic solvent capable of efficiently and reversibly absorbing ammonia gas, which is composed of a pyridine derivative as a hydrogen bond acceptor and a polyhydric alcohol or a polyphenol as a hydrogen bond donor; wherein the pyridine derivative is one of 2-aminopyridine, 3-aminopyridine, 2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine, 2-acetylpyridine and 2-aminomethylpyridine; the polyhydric alcohol is one of glycerol, ethylene glycol, 1,4-butanediol, pentaerythritol, xylitol and sorbitol; and the polyphenol is one of resorcinol, catechol, hydroquinone, pyrogallol and m-trihydroxybenzene.

[0030] The synthesis method of the eutectic solvent comprises the following steps: mixing the pyridine derivative and the hydrogen bond donor at a molar ratio of 1:0.5-1:6, stirring to a uniform liquid state at 60-120℃, further drying under vacuum at 60-120℃ for 24 hours, and finally cooling to room temperature to obtain the final product eutectic solvent.

[0031] The temperature of the low eutectic solvent for absorbing ammonia is 0-80 DEG C, and the absorption pressure is 0.01-0.1 MPa. The absorption can be recycled and regenerated by increasing the temperature and reducing the pressure, and the regeneration temperature is 40-100 DEG C and the regeneration pressure is 0.01-0.1 MPa. The regenerated solvent can be recycled. The regeneration is realized under higher temperature or lower pressure compared with the absorption.

[0032] Example 1

[0033] The preparation process of the 2-aminopyridine / resorcinol system low eutectic solvent is as follows: 1.0003 g of the hydrogen bond acceptor 2-aminopyridine is added into a gourd-shaped bottle, 2.0000 g of the hydrogen bond donor resorcinol is weighed into a 25 ml gourd-shaped bottle according to the molar ratio of 1:2, and then mixed uniformly, and then magnetic stirring is carried out under the condition of 80 DEG C oil bath until a uniform transparent light yellow liquid is formed. The prepared liquid is transferred to a vacuum drying box, dried at 60 DEG C for 24 hours, and then cooled to room temperature to obtain the final product, the low eutectic solvent.

[0034] The ammonia absorption and desorption process of the 2-aminopyridine / resorcinol system low eutectic solvent is as follows: 10.0 g of the low eutectic solvent prepared above is transferred into a glass sample bottle of about 20 ml, ammonia gas with a flow rate of 100 cm 3 / min is introduced under the condition of 40 DEG C water bath, and magnetic stirring is carried out at the same time until the low eutectic solvent absorbs ammonia to saturation. The excess gas is completely absorbed into water or acid solution. The mass of the low eutectic solvent and the absorbed ammonia is obtained by weighing method (the mass of the low eutectic solvent before and after absorbing ammonia is weighed by using an electronic balance, and the mass difference is the mass of the absorbed ammonia). The specific operation of the low eutectic solvent desorption regeneration is as follows: the low eutectic solvent after absorbing ammonia is placed in a 80 DEG C vacuum drying box, the pressure is set to 0.01 MPa, and the low eutectic solvent is placed for 24 hours. The low eutectic solvent after desorption is weighed to obtain the mass of the desorbed ammonia and the residual amount of ammonia.

[0035] The example 1 is repeated under the condition of different molar ratios, and pyridine derivatives are used as the hydrogen bond acceptor and polyols and polyphenols are used as the hydrogen bond donor. The low eutectic solvent composition and molar ratio are shown in Table 1.

[0036] The ammonia absorption and desorption process of the low eutectic solvent based on pyridine derivatives is the same as that of example 1, and the ammonia absorption amount of the low eutectic solvent based on pyridine derivatives is shown in Table 1.

[0037]

[0038]

[0039] Table 1, molar ratio of low eutectic solvent with different compositions and ammonia absorption amount

[0040] The ammonia absorption amount of the eutectic solvent of 2-aminopyridine / resorcinol system in Table 1 changes with time as shown in Figure 1 It can be seen that the eutectic solvent of 2-aminopyridine / resorcinol system has a faster ammonia absorption rate, and its ammonia absorption amount increases with the increase of resorcinol content. When the molar ratio of 2-aminopyridine / resorcinol is 1:2, the ammonia absorption amount reaches the highest, and the results of thermogravimetric analysis and differential scanning calorimetry curves are shown in Figure 2 、 3 It is proved that the eutectic solvent of 2-aminopyridine / resorcinol system has good thermal stability, and the properties are basically stable under the desorption conditions of 80°C, and the experimental results are safe and reliable.

[0041] The preparation process of the eutectic solvent in Example 1 is repeated, and the eutectic solvent of 2-aminopyridine / resorcinol system is prepared under the condition of a molar ratio of 1:2. The ammonia absorption temperature is changed by adjusting the water bath temperature, and the ammonia gas partial pressure is adjusted by adjusting the mixing ratio of nitrogen and ammonia. The experimental results are shown in Table 2, which proves that low temperature and high pressure are beneficial to the absorption of ammonia.

[0042]

[0043]

[0044] Table 2, ammonia absorption amount of eutectic solvent of 2-aminopyridine / resorcinol system under different pressure and temperature

[0045] The ammonia absorption and desorption process of the eutectic solvent in Example 1 is repeated, and the eutectic solvent of 2-aminopyridine / resorcinol system is prepared under the condition of a molar ratio of 1:2. After the desorption operation is completed, 5 repeated tests are carried out, and the results of cyclic desorption are shown in Figure 4 It can be seen that the eutectic solvent of this system has good cyclic performance, and its ammonia absorption capacity has almost no loss after 5 cycles.

[0046] For any person skilled in the art, many possible changes and modifications, or modifications to equivalent embodiments, can be made to the technical solutions of the present application without departing from the scope of the technical solutions of the present application, using the technical content disclosed above. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, which does not deviate from the content of the technical solutions of the present application, should still belong to the scope of protection of the technical solutions of the present application.

Claims

1. An application of a eutectic solvent using a pyridine derivative as a hydrogen bond acceptor, characterized in that, Used for the absorption and capture of ammonia; The eutectic solvent is composed of a pyridine derivative as both a hydrogen bond acceptor and a hydrogen bond donor; the pyridine derivative is one of 2-aminopyridine, 3-aminopyridine, 2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine, 2-acetylpyridine, or 2-aminomethylpyridine; the hydrogen bond donor is a polyol or a polyphenol.

2. The application of the eutectic solvent using pyridine derivatives as hydrogen bond acceptors according to claim 1, characterized in that, The polyol is one of glycerol, ethylene glycol, 1,4-butanediol, pentaerythritol, xylitol, and sorbitol; the polyphenol is one of resorcinol, catechol, hydroquinone, phloroglucinol, and phloroglucinol.

3. The application of the eutectic solvent using pyridine derivatives as hydrogen bond acceptors according to claim 1, characterized in that, The pyridine derivative and the hydrogen bond donor are in a molar ratio of 1:0.5 to 6.

4. The application of the eutectic solvent using pyridine derivatives as hydrogen bond acceptors according to claim 1, characterized in that, The method for preparing the eutectic solvent with pyridine derivative as hydrogen bond acceptor includes the following steps: mixing pyridine derivative and hydrogen bond donor in a molar ratio of 1:0.5 to 6, stirring at 60 to 120°C until homogeneous, drying under vacuum at 60 to 120°C, and cooling to room temperature to obtain the final product.

5. The application of the eutectic solvent using pyridine derivatives as hydrogen bond acceptors according to claim 1, characterized in that, The regeneration temperature is set to 40℃~100℃ and the regeneration pressure is set to 0.01MPa~0.1MPa, so that the eutectic solvent is regenerated in a cyclic manner.

6. The application of the eutectic solvent with pyridine derivatives as hydrogen bond acceptors according to claim 1, characterized in that, The temperature for eutectic solvent absorption of ammonia is set at 0℃~80℃, and the absorption pressure is set at 0.01MPa~0.1MPa.

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