Ionic compounds, absorbents, and absorption devices

Abstract

The present invention provides an ionic compound, an absorbent, and an absorption device. The ionic compound has a structure AB shown in Formula (I) n Formula (I) wherein A is or B is or R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently H, C 1‑6 alkyl; and n is 1 or 2.

Description

Technical Field

[0001] This invention relates to an ionic compound, an absorbent, and an absorption device comprising the same. Background Technology

[0002] Liquid absorbents offer advantages such as high water vapor absorption rate, low regeneration temperature and energy consumption, easy transportation, and long-distance waste heat application, making them widely used in dehumidification systems. Therefore, dehumidification systems utilizing liquid absorbents will be key equipment for reducing carbon emissions and fulfilling corporate environmental responsibility (ESG) in the future.

[0003] Liquid absorbents are liquid materials that directly absorb moisture from the air to achieve dehumidification. The driving force is the difference between the water vapor pressure in the air and the saturated vapor pressure at the surface of the liquid absorbent. Traditional liquid absorbents are aqueous solutions of lithium bromide, lithium chloride, calcium chloride, and magnesium chloride, which are used as liquid absorption media. Due to their strong corrosiveness to metals, these solutions severely affect the reliability and lifespan of dehumidification systems. Although titanium can be used as a heat exchanger to avoid corrosion with traditional salt solutions, this significantly increases the construction cost of the dehumidification system. Furthermore, traditional salt solutions tend to crystallize and precipitate when saturated, reducing dehumidification performance and causing serious system equipment maintenance problems (such as circulation pump blockage).

[0004] Academics and industry have proposed using ionic compounds as liquid absorbents. However, traditional ionic compounds currently used as liquid absorbents still exhibit metal corrosivity, and their water vapor absorption and desorption capabilities still have room for improvement. Summary of the Invention

[0005] According to embodiments of the present invention, an ionic compound is provided. This ionic compound has the structure shown in formula (I).

[0006] AB n Formula (I)

[0007] Where A is B is or R 1 R 2 R 3 R 4 R 5 and R 6 Each is independent as C 1-6 Alkyl group; and n is 1 or 2.

[0008] According to embodiments of the present invention, an absorbent is also provided. This absorbent comprises the ionic compound described in this invention.

[0009] According to an embodiment of the present invention, an absorption device is further provided. The absorption device includes a cavity and the absorbent described in the present invention, wherein the absorbent is disposed within the cavity. Attached Figure Description

[0010] Figure 1 This is a schematic diagram illustrating the absorption device according to an embodiment of the present invention.

[0011] In the attached figures, the following labels are used:

[0012] 10 cavities;

[0013] 20 absorbents; and

[0014] 100 Absorption device. Detailed Implementation

[0015] The following provides a detailed description of the ionic compounds, absorbents, and absorption devices comprising the present invention. It should be understood that the following description provides many different embodiments or examples for implementing different variations of the invention. The specific elements and arrangements described below are merely for illustrative purposes. Of course, these are illustrative only and not intended to limit the invention. In this invention, the term "about" refers to an amount that can be increased or decreased by a magnitude that is generally and reasonably understood by those skilled in the art.

[0016] This invention provides an ionic compound, an absorbent, and an absorption device comprising the same. According to an embodiment of the invention, the ionic compound is composed of a cationic group A and an anionic group B, wherein the cationic group A may be a quaternary ammonium salt cationic group derived from 1,4-diazabicyclo[2.2.2]octane, and the anionic group B may be an anionic group derived from an alkyl phosphate or alkyl sulfate. By combining a specific cationic group A with a specific anionic group B, the liquid absorbent comprising the ionic compound of this invention can have a high hygroscopic capacity and a low desorption temperature (desorption can occur at 60°C or below), thereby increasing the dehumidification efficiency of the absorption device using the absorbent. Furthermore, since the liquid absorbent comprising the ionic compound of this invention has advantages such as being odorless, antibacterial, low corrosive, fluid, and having excellent room temperature storage properties, it can be widely used in various dehumidification equipment.

[0017] According to embodiments of the present invention, an ionic compound is provided. This ionic compound has the structure shown in formula (I).

[0018] Where A can be B can be or R 1 R 2 R 3 R 4 R 5 and R 6 Each is independent as H and C 1-6 Alkyl group; and n is 1 or 2.

[0019] According to embodiments of the present invention, the C of the present invention 1-6 Alkyl groups can be straight-chain or branched. For example, the C group described in this invention... 1-6 The alkyl group can be methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl, or hexyl. Therefore, R 1 R 2 R 3 R 4 R 5 and R 6 Each can be independently methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl, or hexyl.

[0020] According to embodiments of the present invention, the ionic compound may be composed of a cationic group A and an anionic group B. According to embodiments of the present invention, the cationic group A may be a monovalent quaternary ammonium salt cationic group derived from 1,4-diazabicyclo[2.2.2]octane, for example... Furthermore, according to embodiments of the present invention, the cationic group A may be a divalent quaternary ammonium salt cationic group derived from 1,4-diazabicyclo[2.2.2]octane, for example...

[0021] According to embodiments of the present invention, the anionic group B may be an anionic group derived from an alkyl phosphate, for example...

[0022] Furthermore, according to embodiments of the present invention, the anionic group B may be an anionic group derived from an alkyl sulfate, for example...

[0023] According to an embodiment of the present invention, the ionic compound has the structure shown in formula (I).

[0024] AB n Formula (I)

[0025] Where A can be B can be or n can be 1; and R 1 R 4 R 5 and R 6 They can be independently H and C 1-6 Alkyl groups. For example, the ionic compounds described in this invention may be...

[0026] According to an embodiment of the present invention, the preparation method of the above-mentioned ionic compound having a monovalent quaternary ammonium salt cation group may include the following steps: First, 1,4-diazabicyclo[2.2.2]octane is mixed with an anionic precursor to form a mixture. According to an embodiment of the present invention, the anionic precursor may be an alkyl phosphate ester (e.g., Where R 7 R 8 and R 9 They can be independently H and C 1-6 alkyl) or alkyl sulfate (e.g. Where R 10 and R 11 They can be independently H and C 1-6 Alkyl group). According to embodiments of the present invention, the molar ratio of 1,4-diazabicyclo[2.2.2]octane to an anionic precursor may be 1:1 to 1:1.2 to form an ionic compound having a monovalent quaternary ammonium salt cationic group. The mixture is then subjected to a heating process to obtain the ionic compound of the present invention. According to embodiments of the present invention, the temperature of the heating process may be from about 50°C to 150°C, for example 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, or 140°C. According to embodiments of the present invention, the duration of the heating process may be from 1 hour to 24 hours, for example 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 16 hours, or 20 hours.

[0027] According to embodiments of the present invention, before heating the mixture, it may be mixed with a solvent to obtain a solution. According to embodiments of the present invention, the solvent may be toluene, methanol, ethanol, propanol, butanol, ethyl acetate, anisole, butyl acetate, or a combination thereof. According to embodiments of the present invention, the solid content of the solution may be from about 5 wt% to 95 wt%, for example 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, 80 wt%, or 90 wt%. Here, solid content refers to the weight percentage of all components of the solution excluding the solvent, based on the total weight of the solution.

[0028] According to an embodiment of the present invention, the ionic compound has the structure shown in formula (I).

[0029] AB n Formula (I)

[0030] Where A can be B can be or n is 2; and R 2 R 3 R 4 R 5 and R 6 They can be independently H and C 1-6 Alkyl groups. For example, the ionic compounds described in this invention may be...

[0031] According to embodiments of the present invention, the preparation method of the above-mentioned ionic compound having a divalent quaternary ammonium salt cationic group may include the following steps: First, 1,4-diazabicyclo[2.2.2]octane is mixed with an anionic precursor to form a mixture, wherein the molar ratio of 1,4-diazabicyclo[2.2.2]octane to the anionic precursor needs to be 1:2 to 1:3 (e.g., 1:2.2, 1:2.3, 1:2.3, 1:2.4, 1:2.5, or 1:2.8). According to embodiments of the present invention, the anionic precursor may be an alkyl phosphate ester (e.g., Where R 7 R 8 and R 9 They can be independently H and C 1-6 alkyl) or alkyl sulfate (e.g. Among them, H and R 10 and R 11Each can be independently classified as C. 1-6 Alkyl group). The mixture is then subjected to a heating process to obtain the ionic compound described in this invention. According to embodiments of the invention, the temperature of this heating process can be from about 50°C to 150°C, for example, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, or 140°C. According to embodiments of the invention, the duration of this heating process can be from 1 hour to 24 hours, for example, 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 16 hours, or 20 hours.

[0032] According to embodiments of the present invention, before heating the mixture, it may be mixed with a solvent to obtain a solution. According to embodiments of the present invention, the solvent may be toluene, methanol, ethanol, propanol, butanol, ethyl acetate, anisole, butyl acetate, or a combination thereof. According to embodiments of the present invention, the solid content of the solution may be from about 5 wt% to 95 wt%, for example 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, or 80 wt%. Here, solid content refers to the weight percentage of all components of the solution excluding the solvent, based on the total weight of the solution.

[0033] According to embodiments of the present invention, the present invention also provides an absorbent. According to embodiments of the present invention, the absorbent may be composed of the ionic compound described herein.

[0034] According to embodiments of the present invention, the absorbent comprises the ionic compound of the present invention and a solvent, such that the ionic compound is uniformly dispersed or dissolved in the solvent. According to embodiments of the present invention, the weight ratio of the ionic compound to the solvent can be about 1:9 to 9:1, for example 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, or 8:2. According to embodiments of the present invention, the solvent can be water, methanol, ethanol, propanol, butanol, ammonia, or a combination thereof.

[0035] According to an embodiment of the present invention, the absorbent comprises an ionic compound and water, wherein the weight ratio of the ionic compound to the water is 4:1. Here, the viscosity of the absorbent at 15°C can be from approximately 50 cP to 220 cP, for example, 60 cP, 80 cP, 100 cP, 120 cP, 150 cP, 180 cP, or 220 cP.

[0036] According to embodiments of the present invention, the absorbent is in a liquid state within a temperature range of 5°C to 90°C, i.e., has a viscosity in the range of 10 cP to 1,500 cP.

[0037] According to embodiments of the present invention, the absorbent has a large vapor pressure difference in different temperature ranges (e.g., between 15°C and 50°C or between 15°C and 60°C), thus the absorbent has good dehumidification efficiency and low-temperature desorption capability.

[0038] According to an embodiment of the present invention, the present invention further provides an absorption device. Please refer to... Figure 1 The absorption device 100 may include a cavity 10 and the absorbent 20 described in this invention, wherein the absorbent 20 is disposed within the cavity 10. According to an embodiment of the invention, the cavity may be an absorption cavity in which water vapor is absorbed by the absorbent, thereby reducing the water vapor content. Since the absorbent described in this invention has extremely low corrosivity to metals, the construction cost of the absorption device can be reduced. Furthermore, since the absorbent described in this invention has fluidity between 5°C and 90°C, it is also suitable for use in absorption devices employing spray or liquid flow processes.

[0039] To make the above-mentioned and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below.

[0040] Preparation of ionic compound (1)

[0041] Example 1

[0042] Trimethyl phosphate (0.20 mol) and 1,4-diazabicyclo[2.2.2]octane (0.20 mol) were added to a reaction flask, along with toluene (60 mL) as a solvent. After heating at 100 °C for 12 hours, the reaction flask was cooled to room temperature, and the solid was collected. The solid was then dissolved in water (50 mL), and residual toluene and water were removed by rotary condensation. The resulting product was then freeze-dried to obtain ionic compound (1) (structure: (White solid, yield 98%). The reaction equation for the above reaction is shown below:

[0043]

[0044] The spectral information obtained by analyzing ionic compounds (1) using nuclear magnetic resonance spectroscopy is shown below: 1H NMR (400MHz, ppm, CD3OD): δ3.50 (d, J = 8.4Hz, 6H), 3.354 (t, J = 6.0Hz, 6H), 3.20 (t, J = 6.0Hz, 6H), 3.04 (s, 3H).

[0045] Example 2

[0046] Trimethyl phosphate (0.84 mol) and 1,4-diazabicyclo[2.2.2]octane (0.8 mol) were added to a reaction flask, along with 50 mL of n-butanol (n-BuOH) as a solvent. After heating at 60 °C for 12 hours, the reaction flask was cooled to room temperature. The n-butanol was then removed by rotary condensation. The resulting product was then placed in a vacuum oven and baked at 110 °C for 12 hours to give ionic compound (1) (white solid, 98% yield). The reaction equations for the above reaction are shown below:

[0047]

[0048] The spectral information obtained by analyzing ionic compounds (1) using nuclear magnetic resonance spectroscopy is shown below: 1 H NMR (400MHz, ppm, CD3OD): δ3.50 (d, J = 8.4Hz, 6H), 3.354 (t, J = 6.0Hz, 6H), 3.20 (t, J = 6.0Hz, 6H), 3.04 (s, 3H).

[0049] Preparation of ionic compound (2)

[0050] Example 3

[0051] Trimethyl phosphate (0.22 mol) and 1,4-diazabicyclo[2.2.2]octane (0.10 mol) were added to a reaction flask, along with toluene (40 mL) as a solvent. After heating at 100 °C for 12 hours, the reaction flask was cooled to room temperature, and the solid was collected. The solid was then dissolved in water (50 mL), and residual toluene and water were removed by rotary condensation. The resulting product was then freeze-dried to obtain ionic compound (2) (structure: (White solid, yield 92%). The reaction equation for the above reaction is shown below:

[0052]

[0053] The spectral information obtained by analyzing ionic compound (2) using nuclear magnetic resonance spectroscopy is shown below: 1 H NMR (400MHz, ppm, CD3OD): δ4.02(s,12H), 3.58(s,6H), 3.56(s,6H), 3.36(s,6H).

[0054] Example 4

[0055] Trimethyl phosphate (0.44 mol) and 1,4-diazabicyclo[2.2.2]octane (0.2 mol) were added to a reaction flask, along with 50 mL of n-butanol (n-BuOH) as a solvent. After heating at 60 °C for 12 hours, the reaction flask was cooled to room temperature. The n-butanol was then removed by rotary condensation. The resulting product was then placed in a vacuum oven and baked at 110 °C for 12 hours to give ionic compound (2) (white solid, 98% yield). The reaction equations for the above reaction are shown below:

[0056]

[0057] The spectral information obtained by analyzing ionic compound (2) using nuclear magnetic resonance spectroscopy is shown below: 1 H NMR (400MHz, ppm, CD3OD): δ4.02(s,12H), 3.58(s,6H), 3.56(s,6H), 3.36(s,6H).

[0058] Preparation of ionic compound (3)

[0059] Example 5

[0060] Triethyl phosphate (0.2 mol) and 1,4-diazabicyclo[2.2.2]octane (0.2 mol) were added to a reaction flask, along with toluene (60 mL) as a solvent. After heating at 100 °C for 12 hours, the reaction flask was cooled to room temperature, and the lower-layer liquid was collected. The lower-layer liquid was then dissolved in water (100 mL). After extraction three times with diethyl ether (60 mL), the aqueous layer was collected, and activated carbon (1 g) was added. After heating at 50 °C for 4 hours, the result was filtered. The filtrate was then concentrated, dehydrated, and freeze-dried to obtain an ionic compound (3) (structure: (Pale yellow liquid, yield 93%). The reaction equation for the above reaction is shown below:

[0061]

[0062] The spectral information obtained by analyzing ionic compounds (3) using nuclear magnetic resonance spectroscopy is shown below: 1 H NMR (400MHz, ppm, CD3OD): δ3.94-3.82(m,4H), 3.31-3.27(m,8H), 3.18-3.14(m,6H), 1.32(t,J=5.6Hz,3H), 1.21(t,J=5.6Hz,6H).

[0063] Example 6

[0064] Triethyl phosphate (0.42 mol) and 1,4-diazabicyclo[2.2.2]octane (0.4 mol) were added to a reaction flask, along with 40 mL of n-butanol (n-BuOH) as a solvent. After heating at 100 °C for 12 hours, the reaction flask was cooled to room temperature. The mixture was then extracted three times with ethyl acetate (50 mL), and the lower-layer liquid was collected and the solvent removed by rotary condensation. The resulting product was then placed in a vacuum oven and baked at 110 °C for 12 hours to obtain the ionic compound (3) (a pale yellow liquid, yield 92%). The reaction equations for the above reaction are shown below:

[0065]

[0066] The spectral information obtained by analyzing ionic compounds (3) using nuclear magnetic resonance spectroscopy is shown below: 1 H NMR (400MHz, ppm, CD3OD): δ3.94-3.82(m,4H), 3.31-3.27(m,8H), 3.18-3.14(m,6H), 1.32(t,J=5.6Hz,3H), 1.21(t,J=5.6Hz,6H).

[0067] Preparation of ionic compound (4)

[0068] Example 7

[0069] Triethyl phosphate (0.25 mol) and 1,4-diazabicyclo[2.2.2]octane (0.1 mol) were added to a reaction flask, along with toluene (40 mL) as a solvent. After heating at 100 °C for 12 hours, the reaction flask was cooled to room temperature, and the lower-layer liquid was collected. The lower-layer liquid was then dissolved in water (80 mL). After extraction three times with diethyl ether (50 mL), the aqueous layer was collected, and activated carbon (1 g) was added. After heating at 50 °C for 4 hours, the result was filtered. The filtrate was then concentrated to remove water and freeze-dried to obtain ionic compound (4) (structure: (Pale yellow liquid, yield 90%). The reaction equation for the above reaction is shown below:

[0070]

[0071] The spectral information obtained by analyzing ionic compounds (4) using nuclear magnetic resonance spectroscopy is shown below: 1 H NMR (400MHz, ppm, CD3OD): δ3.95 (s, 12H), 3.88 (quint, J = 5.6Hz, 8H), 3.64 (q, J = 5.6Hz, 4H), 1.43 (t, J = 5.6Hz, 6H), 1.23 (t, J = 5.6Hz, 12H).

[0072] Example 8

[0073] Triethyl phosphate (0.25 mol) and 1,4-diazabicyclo[2.2.2]octane (0.1 mol) were added to a reaction flask, along with 1-butanol (n-BuOH) (20 mL) as a solvent. After heating at 140 °C for 12 hours, the reaction flask was cooled to room temperature. The mixture was then extracted three times with ethyl acetate (40 mL), and the lower-layer liquid was collected and the solvent removed by rotary condensation. The resulting product was then placed in a vacuum oven and baked at 110 °C for 12 hours to obtain ionic compound (4) (a pale yellow liquid, yield 92%). The reaction equations for the above reaction are shown below:

[0074]

[0075] The spectral information obtained by analyzing ionic compounds (4) using nuclear magnetic resonance spectroscopy is shown below:1 H NMR (400MHz, ppm, CD3OD): δ3.95 (s, 12H), 3.88 (quint, J = 5.6Hz, 8H), 3.64 (q, J = 5.6Hz, 4H), 1.43 (t, J = 5.6Hz, 6H), 1.23 (t, J = 5.6Hz, 12H).

[0076] Comparative Example 1

[0077] Triethyl phosphate (0.3 mol) and 1-methylimidazole (0.3 mol) were added to a reaction flask. After heating at 140 °C for 12 hours, the reaction flask was cooled to room temperature, and the result was dissolved in water (80 mL). After extraction three times with diethyl ether (50 mL), the aqueous layer was collected and activated carbon (1 g) was added. After heating at 50 °C for 4 hours, the result was filtered. Then, the filtrate was concentrated, dehydrated, and freeze-dried to obtain ionic compound (5) (structure: (Pale yellow liquid, yield 90%). The reaction equation for the above reaction is shown below:

[0078]

[0079] The spectral information obtained by analyzing ionic compounds (5) using nuclear magnetic resonance spectroscopy is shown below: 1 H NMR (400MHz, ppm, CD3OD): δ8.95(s,1H),7.66(s,1H),7.59(s,1H),4.27(q,J=6.0Hz,2H ), 3.94 (s, 3H), 3.91 (quint, J = 5.6Hz, 4H), 1.55 (t, J = 6.0Hz, 3H), 2.26 (t, J = 5.6Hz, 6H).

[0080] Comparative Example 2

[0081] 0.1 mol of 2-(N,N-dimethylamino)ethanol (DMAE) was added to a reaction flask. Then, 0.1 mol of trimethyl phosphate was slowly added dropwise to the reaction flask at 0°C. After heating at 55°C for 24 hours, the reaction flask was cooled to room temperature, and a white solid precipitated. The solid was dissolved in water (50 mL). After extraction three times with diethyl ether (30 mL), the aqueous layer was collected. After removing water by rotary evaporation, the result was placed in a vacuum oven and baked at 60°C for 12 hours to obtain ionic compound (6) (structure: (Pale yellow liquid, yield 92%). The reaction equation for the above reaction is shown below:

[0082]

[0083] The spectral information obtained by analyzing ionic compounds (6) using nuclear magnetic resonance spectroscopy is shown below: 1 H NMR (400MHz, ppm, CD3OD): δ3.99-3.96(m,2H),3.55(s,3H),3.53(s,3H),3.48-3.46(m,2H),3.20(s,9H).

[0084] Preparation of absorbent

[0085] Example 9

[0086] Ionic compound (1) was mixed with water in a weight ratio of 4:1. After uniform stirring, absorbent (1) was obtained.

[0087] Examples 10-12

[0088] Examples 10-12 were carried out as described in Example 9, except that the ionic compound (1) was replaced with ionic compounds (2)-(4) respectively to obtain absorbents (2)-(4).

[0089] Comparative Examples 3 and 4

[0090] Comparative Examples 3 and 4 were carried out in the manner described in Example 9, except that the ionic compound (1) was replaced with ionic compounds (5) and (6) respectively, to obtain absorbents (5) and (6).

[0091] Comparative Example 5

[0092] Provides ionic compounds (7) (structure is The ionic compound (7) was mixed with water in a weight ratio of 4:1. After uniform stirring, absorbent (7) was obtained.

[0093] Comparative Example 6

[0094] Provides ionic compounds (8) (structure is The ionic compound (8) was mixed with water in a weight ratio of 4:1. After uniform stirring, the absorbent (8) was obtained.

[0095] Comparative Example 7

[0096] Provides ionic compounds (9) (structure is) The ionic compound (9) was mixed with water in a weight ratio of 4:1. After uniform stirring, absorbent (9) was obtained.

[0097] Comparative Example 8

[0098] Lithium chloride (LiCl) is provided. Lithium chloride is mixed with water in a weight ratio of 1:2. After uniform stirring, absorbent (10) is obtained.

[0099] Water vapor pressure measurement

[0100] The vapor pressure of water vapor in absorbents (1)-(4) was measured at 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, and 60℃, and the vapor pressure difference of absorbents (1)-(4) at different temperatures was calculated. The results are shown in Table 1. In addition, the vapor pressure of water vapor in absorbents (5)-(10) was measured at 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, and 60℃, and the vapor pressure difference of absorbents (5)-(10) at different temperatures was calculated. The results are shown in Table 2.

[0101] The water vapor pressure of the absorbent was measured using the boiling point method (reference (J. Chem. Eng. Data 2004, 49, 1550-1553)). The steps are as follows: The absorbent was placed in a container and the temperature was lowered to 5°C. After evacuating the container until the water vapor began to evaporate, the vacuum was turned off and heating began. The vapor pressure was measured using a pressure gauge (model EJX310A, YOKOGAWA) every 5°C increase.

[0102] Table 1

[0103]

[0104]

[0105] Table 2

[0106]

[0107]

[0108] The water vapor pressure measured by the absorbent (10) (lithium chloride aqueous solution) of the present invention is comparable to the value described in relevant literature (Applied Thermal Engineering 2017, 124, 271–278).

[0109] The dehumidification capacity of an absorbent can be assessed using its water vapor pressure. When an absorption device is operating, the absorbent absorbs moisture from the environment to reduce humidity, driven by the difference between the water vapor pressure in the air and the saturated vapor pressure at the absorbent's surface. The extent to which the absorbent dehumidifies the air to its lowest relative humidity limit can be assessed by the absorbent's water vapor pressure. The lower the absorbent's water vapor pressure, the stronger its moisture absorption capacity at that temperature (i.e., an aqueous solution of an ionic compound).

[0110] As shown in Table 1, when the ionic compounds of the present invention are prepared as absorbents, their water vapor pressure at 5-20°C can be less than or equivalent to 1.1 kPa.

[0111] Furthermore, a lower water vapor pressure indicates a more hydrophilic nature (making it less likely to desorb water), and water vapor pressure increases with temperature. Therefore, a greater vapor pressure difference between different temperatures indicates a larger amount of water vapor that can be adsorbed and desorbed within that temperature range (i.e., a greater dehumidification capacity). Thus, a greater vapor pressure difference between different temperatures indicates higher dehumidification efficiency (i.e., the absorbent has a higher dehumidification capacity).

[0112] As shown in Table 2, although lithium chloride aqueous solution has a low water vapor pressure at low temperatures (i.e., it has good hydrophilicity), the vapor pressure difference (Vp) is relatively high. 60-15 The low value indicates that lithium chloride aqueous solution still does not easily desorb water at 60°C (it needs to be heated to a higher temperature), increasing the energy consumption for absorbent regeneration.

[0113] As shown in Tables 1 and 2, the vapor pressure difference (Vp) of the absorbents (i.e., absorbents (1)-(4)) prepared using the ionic compounds described in this invention between 15°C and 50°C is [not specified]. 50-15 ) and vapor pressure (Vp) between 15 and 60°C 60-15 The vapor pressure difference of the ionic compound is greater than that of the lithium chloride aqueous solution (i.e., absorbent (10)). Therefore, the ionic compound of the present invention can reduce the regeneration energy consumption of the absorbent and improve the dehumidification efficiency of the absorbent.

[0114] Corrosion test

[0115] Available in copper (C1100P) (size 10 x 10 x 2 mm) 3 ), and weighed. Next, copper was placed into sample bottles containing different absorbents (i.e., absorbents (1)-(10)) (8mL) and tap water respectively. After stirring and reacting at 80℃ for 2 days, the copper was taken out, cleaned and dried and weighed, and the percentage change in weight of copper was calculated. The results are shown in Table 3. Next, aluminum (A5052) (size 10x10x2 mm) was used respectively. 3 ) and stainless steel (SUS304) (size 10x10x2 mm) 3Replace copper and repeat the above steps. The results are shown in Table 3.

[0116] Table 3

[0117]

[0118]

[0119] As shown in Table 3, lithium chloride and absorbents (5-10) exhibit varying degrees of corrosivity to stainless steel, aluminum, and copper. Furthermore, as shown in Table 3, the absorbents (i.e., absorbents (1)-(4)) prepared using the ionic compounds described in this invention exhibit almost no corrosivity to stainless steel and aluminum, and also have low corrosivity to copper.

[0120] Viscosity Measurement

[0121] The viscosity values ​​of absorbents (1)-(4) at different temperatures were measured using a viscometer (model DV-II+Pro, Brookfield), and the results are shown in Table 4.

[0122] Table 4

[0123]

[0124]

[0125] Viscosity is also one of the indicators for evaluating absorbents. If the viscosity of the absorbent is too low, it is easily carried over into the air, causing environmental pollution. If the viscosity of the absorbent is too high, the fluidity of the absorbent decreases, increasing the energy consumption of the pump. As shown in Table 4, the absorbent prepared using the ionic compound of the present invention has a viscosity at 15°C in the range of 50 cP to 220 cP, making it suitable for dehumidification systems using spray or liquid flow processes.

[0126] Odor and Degradation Assessment

[0127] Since the air introduced by the dehumidification system comes into direct contact with the absorbent, ionic compounds that produce an odor are less suitable for air conditioning systems. The absorbents (1)-(4) prepared from the ionic compounds (1)-(4) of this invention were stored at room temperature and pressure for 180 days. After evaluation, the absorbents (1)-(4) showed no degradation and produced no noticeable odor.

[0128] In summary, absorbents containing the ionic compounds described in this invention can have high hygroscopic capacity and low desorption temperature, thereby increasing the dehumidification efficiency of absorption devices utilizing such absorbents. Furthermore, because liquid absorbents containing the ionic compounds described in this invention have advantages such as being odorless, antibacterial, low-corrosive, fluid, and having excellent room-temperature storage properties, they can be widely used in various dehumidification equipment.

[0129] Although the present invention has been disclosed above with reference to several embodiments, it is not intended to limit the present invention. Anyone with common knowledge in the art can make any modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the appended claims.

Claims

1. An ionic compound having the structure shown in formula (I): AB n Formula (I) in, A is or B is ;R 1 R 2 R 3 R 4 and R 5 Each is independently either methyl or ethyl; and n is 1 or 2.

2. An absorbent comprising: An ionic compound, wherein the ionic compound is the ionic compound of claim 1.

3. The absorbent according to claim 2, further comprising: A solvent, wherein the weight ratio of the ionic compound to the solvent is 1:9 to 9:

1.

4. The absorbent according to claim 3, wherein the solvent is water, methanol, ethanol, propanol, butanol, ammonia, or a combination thereof.

5. The absorbent according to claim 3, wherein the solvent is water, and the weight ratio of the ionic compound to the water is 4:1, wherein the absorbent has a viscosity of 50 cP to 220 cP at 15°C.

6. An absorption device, comprising: A cavity; and An absorbent is placed in the cavity, wherein the absorbent is the absorbent according to claim 2.

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