KR102365539B1 - Carbon dioxide absorbent and air purifier including the same - Google Patents

Abstract

A carbon dioxide adsorbent is disclosed. The carbon dioxide adsorbent includes metal-organic frameworks (MOFs) bonded to an amine group of an amine compound, and the amine compound is N-methyl-1,3-diaminopropane (N-methyl-1,3- diaminopropane) or 1,3-diaminopentane (1,3-diaminopentane).

Description

Carbon dioxide adsorbent and air purifier including same {CARBON DIOXIDE ABSORBENT AND AIR PURIFIER INCLUDING THE SAME}

The present disclosure relates to a carbon dioxide adsorbent and an air purifying device including the same, and more particularly, to a carbon dioxide adsorbent having a carbon dioxide adsorption capacity applicable to real life and renewable at a low temperature, and an air purifying device including the same.

Various gases exist in indoor air. In particular, carbon dioxide in the indoor air is used as an indicator of indoor air pollution, and if the concentration of carbon dioxide in the indoor air is high, the possibility of causing an image to the human body increases. For example, as the concentration of carbon dioxide in the indoor air increases, physical conditions such as feeling drowsy may worsen, or symptoms such as stiff shoulders, headache, and dizziness may occur. In addition, research results show that as the concentration of carbon dioxide increases, movement during sleep increases and the quality of sleep decreases overall. The recommended standard for carbon dioxide concentration is 1000 ppm (ASHRAE in Korea, Japan, and the United States).

While the concentration of carbon dioxide in the outdoor air is maintained at about 400 ppm, the concentration of carbon dioxide in a closed room may increase rapidly if ventilation is not performed frequently due to outdoor dust. Based on the occupancy of 4 people in a 10-pyeong living room, the concentration of carbon dioxide exceeds 2000 ppm in one hour, and the change in concentration in a narrow space such as a personal vehicle and an express bus is even more rapid.

As a result of measurement in the living room of 10 apartment units across downtown Seoul, the concentration of carbon dioxide showed a concentration distribution of 600 to 1200 ppm regardless of sleeping, cooking, and ventilation times, with a maximum of 1600 ppm or more. Therefore, it was necessary to develop a technology capable of removing carbon dioxide from the indoor carbon dioxide concentration, that is, at a concentration of about 1000 ppm.

As a conventional carbon dioxide removal technology, there was a wet scrubbing technology for removing carbon dioxide in the exhaust gas of a factory, but the carbon dioxide concentration in the exhaust gas is as high as about 15%, so if it is applied indoors where the carbon dioxide concentration is around 0.04%, the performance deteriorates has occurred. In addition, since the carbon dioxide removal device for flue gas uses a liquid-based absorbent, it is difficult to apply it to home appliances.

In addition, the conventional carbon dioxide removal device has a problem in that excessive energy is consumed because a high temperature exceeding 100° C. is required to adsorb and then desorb carbon dioxide and reuse it.

The present disclosure has been made out of the above needs, and an object of the present disclosure is to provide a carbon dioxide adsorbent having a carbon dioxide adsorption capacity applicable to real life and renewable at a low temperature, and an air purification device including the same.

The carbon dioxide adsorbent according to an embodiment of the present disclosure includes metal-organic frameworks (MOFs) bonded to an amine group of an amine compound, and the amine compound is N-methyl-1,3-diaminopropane ( N-methyl-1,3-diaminopropane) or 1,3-diaminopentane (1,3-diaminopentane).

In this case, the amine compound may be N-methyl-1,3-diaminopropane.

Meanwhile, the amine compound may be 1,3-diaminopentane.

On the other hand, the metal-organic framework is selected from the group consisting of M2 (dobpdc), M2 (dobdc), M2 (dondc) and M2 (dotpdc), wherein the metal M is Mg, Ti, V, Cr, Mn, Co , Ni, Fe, Cu or Zn, dobpdc is 4,4'-dioxido-3,3'-biphenyldicarboxylate, dobdc is 2,5-dioxido-1,4-benzenedicarboxylate rate, dondc may be 1,5-dioxide-2,6-naphthalenedicarboxylate, and dotpdc may be 4,4'-dioxido-3,3'-triphenyldicarboxylate.

In this case, the metal-organic framework may be Mg ₂ (dobpdc).

Meanwhile, when the carbon dioxide adsorbent is heated to a temperature not exceeding 70° C., 90% or more of the adsorbed carbon dioxide may be desorbed.

On the other hand, the air purifier according to an embodiment of the present disclosure includes a carbon dioxide adsorbent for collecting carbon dioxide and a heater for generating heat for desorbing carbon dioxide adsorbed on the carbon dioxide adsorbent, wherein the carbon dioxide adsorbent is an amine compound. and metal-organic frameworks (MOFs) bonded to an amine group, wherein the amine compound is N-methyl-1,3-diaminopropane or 1,3 - It is selected from diaminopentane (1,3-diaminopentane).

In this case, the heater may generate heat so that the temperature of the carbon dioxide adsorbent does not exceed 70°C.

Meanwhile, the air purifier may be a home appliance.

1 is a schematic diagram of an example of a metal-organic skeleton;
FIG. 2 is a diagram illustrating an example of carbon dioxide adsorption/desorption of an amine functionalized metal-organic framework in FIG. 2;
Figure 3a is a diagram showing the adsorption isotherm for the carbon dioxide adsorbent of Example 1 (nmpn-Mg ₂ (dobpdc));
Figure 3b is a diagram showing the adsorption isotherm for the carbon dioxide adsorbent of Example 2 (epn-Mg ₂ (dobpdc));
3c is a graph showing the adsorption isotherm for the carbon dioxide adsorbent of Example 3 (men-Mg ₂ (dobpdc));
3D is a graph showing the adsorption isotherm for the carbon dioxide adsorbent of Example 4 (dmpn-Mg ₂ (dobpdc));
3E is a plot showing the adsorption isotherm versus the adsorption isotherm for the carbon dioxide adsorbent of Example 5 (Ndmpn-Mg ₂ (dobpdc));
4A is a view showing a thermogravimetric analysis (TGA) curve for the carbon dioxide adsorbent of Example 1;
Figure 4b is a diagram showing the TGA curve for the carbon dioxide adsorbent of Example 2;
4c is a diagram showing the TGA curve for the carbon dioxide adsorbent of Example 3;
4D is a diagram showing the TGA curve for the carbon dioxide adsorbent of Example 4;
Figure 4e is a diagram showing the TGA curve for the carbon dioxide adsorbent of Example 5;
Figure 5a is a graph showing the adsorption and desorption cycle of the carbon dioxide adsorbent of Example 1;
Figure 5b is a graph showing the adsorption and desorption cycle of the carbon dioxide adsorbent of Example 2;
Figure 6a is a graph showing the results of measuring the repeated usability in the chamber under real life conditions of the carbon dioxide adsorbent of Example 1;
6b is a graph showing the results of measuring repeated usability in the chamber under real-life conditions of the carbon dioxide adsorbent of Example 2;
6c is a graph showing the results of measuring repeated usability in the chamber under real life conditions of the carbon dioxide adsorbent of Example 3;

In describing the present disclosure, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present disclosure, the detailed description thereof will be omitted. In addition, the terms to be described later are terms defined in consideration of functions in the present disclosure, which may vary depending on the intention or relationship of a user or an operator. Therefore, the definition should be made based on the content throughout this specification.

The terms used in the present disclosure are used only to describe specific embodiments, and are not intended to limit the scope of rights. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as "comprises" or "consisting of" are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, and are intended to indicate that one or more other It should be understood that this does not preclude the possibility of addition or presence of features or numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, the present disclosure will be described in more detail.

The carbon dioxide adsorbent according to the present disclosure includes metal-organic frameworks (MOFs) as a basic structure.

The metal-organic framework is a crystalline porous material having a three-dimensional structure consisting of a coordination bond between a metal ion and an organic ligand connecting it. A schematic diagram of an example of a metal-organic framework is shown in FIG. 1 . Depending on the choice of metal ions and organic ligands, pore size control, high crystallinity and large surface area, and various surface functionalizations are possible. In particular, the metal-organic framework exhibits a specific surface area of 5,000 m ² /g or more, which is the highest value among porous materials and is advantageous for gas adsorption. Metalorganic frameworks have coordinatingly unsaturated open metal sites lying along the pore surface, and these coordinating metal cations behave as Lewis acids that strongly polarize the gas and can facilitate postsynthetic functionalization.

According to the present disclosure, the metal-organic framework may be selected from the group consisting of M2 (dobpdc), M2 (dobdc), M2 (dondc) and M2 (dotpdc). In this case, the metal M may be Mg, Ti, V, Cr, Mn, Co, Ni, Fe, Cu or Zn, preferably Mg. where dobpdc is 4,4'-dioxido-3,3'-biphenyldicarboxylate, dobdc is 2,5-dioxido-1,4-benzenedicarboxylate, and dondc is 1,5- Dioxide is 2,6-naphthalenedicarboxylate, and dotpdc is 4,4'-dioxido-3,3'-triphenyldicarboxylate.

According to an embodiment of the present disclosure, a carbon dioxide adsorbent including a metal-organic framework grafted with an amine compound is preferable. Since the amine group of the amine compound is bonded to the metal-organic framework, the amine compound may be grafted to the metal-organic framework. The amine group of the amine compound containing nitrogen having basicity may improve the amount of carbon dioxide adsorption.

According to an embodiment, a diamine compound grafted onto a metal-organic framework may be used. One amine in the diamine molecule can bind to the metal cation of the metalorganic framework as a Lewis base, and the other amine undergoes strong physical and chemical adsorption with carbon dioxide entering the pores of the metalorganic framework. As such, an example of carbon dioxide adsorption/desorption of the amine-functionalized metal-organic framework is shown in FIG. 2 .

According to various embodiments of the present disclosure, the amine compound for amine functionalization of the metal-organic framework may be selected from compounds of Formulas 1 to 5 shown in Table 1 below.

N-메틸-1,3-디아미노프로판[Formula 1]

N-Methyl-1,3-diaminopropane [Formula 2]

1,3-diaminopentane [Formula 3]

1,2-diaminopropane [Formula 4]

2,2-dimethyl-1,3-diaminopropane [Formula 5]

N,N-Dimethyl-1,3-diaminopropane

In particular, it is preferable to use a compound of the above formula (1) or (2) as the amine compound. When the metal-organic framework functionalized with the compound of Formula 1 or Formula 2 is used as an adsorbent, the maximum adsorption amount based on 1000 ppm of carbon dioxide is 15.24 wt%, which is a very high level. It was confirmed that the performance was maintained at wt% (in addition to 0.04% carbon dioxide, 78% nitrogen, 21% oxygen, and a large amount of moisture exist in the air in real life, so the adsorption amount is maintained even though there are sufficient factors to prevent carbon dioxide adsorption).

In addition, as a result of drawing an isothermal adsorption line according to pressure using an adsorbent containing a metal-organic framework functionalized with a compound of Formula 1 or Formula 2, a step-shaped isotherm was shown between 400 and 1000 ppm, usually (carbon dioxide concentration of 400 ppm). It has the property of maximizing adsorption when the concentration of carbon dioxide increases and exceeds 1000 ppm while adsorption is low.

In addition, in order to regenerate the carbon dioxide adsorbent, heat must be applied to desorb the adsorbed carbon dioxide. The adsorbent containing the metal-organic framework functionalized with the compound of Formula 1 or Formula 2 contains 90% of carbon dioxide even when heated to about 70°C. The abnormality may be detached. Compared to the conventional carbon dioxide adsorbent having a metal-organic skeleton as a basic structure, in which carbon dioxide can be significantly desorbed when heated to 100° C. or higher, energy consumption when using the adsorbent according to embodiments of the present disclosure can be significantly reduced.

In addition, the performance of the adsorbent containing the metal-organic framework functionalized with the compound of Formula 1 or Formula 2 is maintained at 90% or more even when repeated tests at 70° C. for 30 or more repeated tests, and when the humidity is raised to 60%RH or more performance is maintained over 90%.

Meanwhile, according to another embodiment of the present disclosure, an air purification device including the carbon dioxide adsorbent of the present disclosure may be provided.

Specifically, the air purifier according to an embodiment of the present disclosure may include a heater that generates heat to desorb the carbon dioxide adsorbent and the carbon dioxide adsorbent according to the present disclosure.

Since the carbon dioxide adsorbent according to the present disclosure can be easily desorbed from carbon dioxide even at about 70°C, the heater can generate heat so that the temperature of the carbon dioxide adsorbent does not exceed 70°C.

According to an embodiment, the air purifier may include an exhaust pipe connected to the outside, and carbon dioxide desorbed from the carbon dioxide adsorbent may be discharged through the exhaust pipe.

On the other hand, the air purification device according to another embodiment of the present disclosure includes a traveling unit for moving the air purification device, a fan for sucking air, a carbon dioxide adsorbent of the present disclosure, and desorbing carbon dioxide adsorbed on the carbon dioxide adsorbent. It may include a heater that generates heat for the purpose, and may include a computing device that controls the overall operation of the air purifier. Such an air purifier may automatically move to a ventilable place when it is desired to regenerate the carbon dioxide adsorbent by desorbing the carbon dioxide adsorbed to the carbon dioxide adsorbent.

For example, the driving unit of the air purifier according to the present embodiment may include a motor and one or more wheels.

In addition, the computing device of the air purifier according to the present embodiment may calculate the period of use of the carbon dioxide adsorbent, and when the used period elapses a preset period, it may determine that regeneration of the carbon dioxide adsorbent is required. In addition, the computing device may communicate with an external device, and may determine whether indoor ventilation is in progress and a ventilable area based on information received from a sensing device attached to at least one of external windows and doors, and the result of the determination By controlling the driving unit based on the Therefore, the carbon dioxide adsorbed on the carbon dioxide adsorbent in the ventilation area can be desorbed and discharged.

The air purifier according to the above-described various embodiments may be implemented as a home appliance applicable in real life. For example, it may be implemented as a robot cleaner, an air conditioner, an air purifier, a humidifier, and the like.

Hereinafter, embodiments for better understanding of the present disclosure will be described. The following examples are provided to help the understanding of the present disclosure, but the scope of the present disclosure is not limited thereto.

1. Manufacturing Example

1.1 [Mg ₂ (dobpdc)(DMF) ₂ ] manufacturing

H ₄ dobpdc (7.8423 g, 28.598 mmol), MgCl ₂ .6H2O (11.6278g, 57.195 mmol), and 200 ml of a mixed solution (DMF:EtOH=1:1 / volume:volume) were placed in a 300 ml autoclave. Sealed well with a lid. The mixture was reacted at 140 °C for 72 hours. After the reaction mixture was filtered, a purple solid was obtained, washed several times with N,N-dimethylformamide (DMF), and dried under vacuum conditions. As a result, [Mg ₂ (dobpdc)(DMF) ₂ ] having a yield rate of about 90% was obtained.

1.2 mg ₂ (dobpdc)(Nmpn or epn or men or dmpn or Ndmpn) _1.8 (H2O) _0.2 [Amine-Mg ₂ (dobpdc)] manufacturing

[Mg ₂ (dobpdc)(DMF) ₂ ] was put in MeOH for 3 days to remove DMF, and [Mg ₂ (dobpdc)(MeOH) ₂ ] was made. After sufficiently filtering MeOH, the MeOH in the surface and pores was removed by using nitrogen gas or creating a vacuum.

1 g (1 equivalent) of a dry material from which MeOH has been sufficiently removed, 160 equivalents of amine in 70 ml of toluene is added to the flask, followed by sonication for 12 hours (N-methyl-1,3-diaminopropane (nmpn), 1 ,3-diaminopentane (epn), 1,2-diaminopropane (men), 2,2-dimethyl-1,3-diaminopropane (dmpn), N,N-dimethyl-1,3-diamino Also done separately for each propane (Ndmpn)). After the reaction was completed, a purple solid was separated using a filter and washed several times with hexane to remove toluene. Then, using nitrogen gas or drying under vacuum conditions. ( Example 1 : nmpn-Mg2 (dobpdc), Example 2: epn-Mg2 (dobpdc), Example 3 : men-Mg2 (dobpdc), Example 4 : dmpn-Mg2 (dobpdc), Example 5: Ndmpn -Mg2(dobpdc)).

2. Evaluation of carbon dioxide adsorbent performance

2.1 Evaluation of adsorption performance at isothermal conditions

In order to evaluate the adsorption properties of the carbon dioxide adsorbent, the adsorption isotherm was measured. 3A is an adsorption isotherm for the adsorbent of Example 1, FIG. 3B is an adsorption isotherm for the adsorbent of Example 2, FIG. 3C is an adsorption isotherm for the adsorbent of Example 3, FIG. 3D is an adsorption isotherm for the adsorbent of Example 4 isotherms, and FIG. 3E shows the adsorption isotherms for the adsorbent of Example 5.

Referring to FIGS. 3A to 3E , it can be seen that the adsorption performance is different depending on the amine compound grafted to the metal-organic framework. In particular, for the adsorption isotherm for the adsorbent of Example 1 (FIG. 3A), the adsorption isotherm for the adsorbent of Example 2 (FIG. 3B), and the adsorption isotherm for the adsorbent of Example 3, 0.4 to 1 mbar (400 to 1000 ppm) It differs from the adsorption isotherm for the adsorbent of Example 4 ( FIG. 3D ) and the adsorption isotherm for the adsorbent of Example 5 ( FIG. 3E ) in that the adsorption starts abruptly at . Therefore, the adsorbents of Examples 1, 2 and 3 are adsorbed when the carbon dioxide concentration is increased to 1000 ppm or more due to the absence of ventilation, and the carbon dioxide adsorption is minimized in normal life (carbon dioxide concentration 400 ppm or less) in real life such as at home. This can be maximized, and it can be seen that the property has properties suitable for real-life applications.

2.2 Evaluation of adsorption performance according to temperature change

Using thermogravimetric analysis (TGA), the adsorption pattern was confirmed while varying the temperature in an environment with a carbon dioxide concentration of 1000 ppm. 1000ppm is the concentration of carbon dioxide that can appear in real life such as at home, and is very low compared to the concentration of carbon dioxide in the exhaust gas of a factory. 4A is a TGA curve for the adsorbent of Example 1, FIG. 4B is a TGA curve for the adsorbent of Example 2, FIG. 4C is a TGA curve for the adsorbent of Example 3, FIG. 4D is a TGA curve for the adsorbent of Example 4 curve, and FIG. 4e shows the TGA curve for the adsorbent of Example 5.

In particular, looking at the TGA curve of the adsorbent of Example 1 ( FIG. 4a ) and the TGA curve of Example 2 ( FIG. 4b ), it can be seen that the adsorption is good even in a low-concentration carbon dioxide environment, and 90% at a low temperature of 70°C It can be seen that the abnormal carbon dioxide is desorbed. In addition, it can be seen that the adsorbent of Example 3 also adsorbed better than the adsorbent of Example 4 and the adsorbent of Example 5.

Meanwhile, the regeneration rate of the adsorbents according to an embodiment of the present disclosure will be described below. The adsorbents of Examples 4 and 5 hardly adsorbed, so there is no meaning in confirming the regeneration rate, and the regeneration rates of the adsorbents of Examples 1 to 3 are shown in the table below.

Regeneration temperature [℃] 50℃ 60℃ 70℃ 80℃ 90℃ 100℃ Example 1 35% 65% 96% 97% 98% 99% Example 2 37% 94% 98% 99% 99% 100% Example 3 9% 19% 29% 43% 66% 86%

The adsorbent of Example 1 shows a regeneration rate of 96% or more from 70°C, and the adsorbent of Example 2 already shows a regeneration rate of 94% or more at 60°C. However, in the case of the adsorbent of Example 3, although adsorption is good as described above, a high temperature is required for regeneration, and it was confirmed that the regeneration rate was only 86% even when the temperature was raised to 100°C. Accordingly, when the adsorbent of Example 1 and the adsorbent of Example 2 are used, energy consumption can be reduced compared to the case of using the adsorbent of Example 3 in that a high temperature for regeneration is not required.

2.3 Repeatability evaluation

5A is a graph showing the adsorption and desorption cycle of the carbon dioxide adsorbent of Example 1, and FIG. 5B is a graph showing the adsorption and desorption cycle of the carbon dioxide adsorbent of Example 2. Specifically, FIGS. 5A and 5B show that the adsorbents prepared according to Examples 1 and 2 maintain their performance even in 10 adsorption/desorption processes at a low temperature of 70° C., and also in repeated performance tests of 9 or more times. It indicates that high performance of 10 wt% or more is maintained. In other words, it was confirmed that the adsorbents prepared according to Examples 1 and 2 maintained excellent carbon dioxide adsorption performance even when reused.

2.4 Confirmation of repeatability in real environment

6A to 6C are results of measuring repeated usability in a chamber under real-life conditions in order to check whether the same level of adsorption is maintained even under real-life conditions including nitrogen, oxygen, and moisture as well as carbon dioxide. 6A, 6B, and 6C are graphs of carbon dioxide adsorbents prepared according to Examples 1, 2, and 3, respectively. 6A to 6C, when all of the carbon dioxide adsorbents of Examples 1, 2 and 3 are regenerated at 130° C. in a chamber under real-life conditions, repeated use is possible, and even if the regeneration temperature is lowered, Example 1 and It can be seen that the carbon dioxide adsorbent of Example 2 can be used repeatedly, but the regeneration ability of the carbon dioxide adsorbent of Example 3 is reduced. Therefore, it can be seen that the adsorbents of Examples 1 and 2 are excellent in repeatability even in real life.

In the above, preferred embodiments of the present disclosure have been illustrated and described, but the present disclosure is not limited to the specific embodiments described above, and is generally used in the technical field belonging to the present disclosure without departing from the gist of the present disclosure as claimed in the claims. Various modifications may be made by those having the knowledge of

Claims (9)

In the carbon dioxide adsorbent,
Includes metal-organic frameworks (MOFs) bonded to the amine group of the amine compound,
The amine compound is selected from N-methyl-1,3-diaminopropane or 1,3-diaminopentane,
The carbon dioxide adsorbent,
A carbon dioxide adsorbent wherein at least 90% of the adsorbed carbon dioxide is desorbed when heated to a temperature not exceeding 70°C. According to claim 1,
The amine compound is N-methyl-1,3-diaminopropane, carbon dioxide adsorbent. According to claim 1,
The amine compound is 1,3-diaminopentane, carbon dioxide adsorbent. 4. The method according to any one of claims 1 to 3,
The metal-organic framework is selected from the group consisting of M2 (dobpdc), M2 (dobdc), M2 (dondc) and M2 (dotpdc),
where M is Mg, Ti, V, Cr, Mn, Co, Ni, Fe, Cu or Zn, dobpdc is 4,4'-dioxido-3,3'-biphenyldicarboxylate, and dobdc is 2,5-dioxido-1,4-benzene dicarboxylate, dondc is 1,5-dioxide-2,6-naphthalenedicarboxylate, dotpdc is 4,4'-dioxido-3, 3'-triphenyldicarboxylate, a carbon dioxide adsorbent. 5. The method of claim 4,
The metal-organic framework is Mg ₂ (dobpdc), a carbon dioxide adsorbent. delete In the air purifier,
a carbon dioxide adsorbent for capturing carbon dioxide; and
a heater for generating heat for desorbing the carbon dioxide adsorbed to the carbon dioxide adsorbent;
The carbon dioxide adsorbent,
Includes metal-organic frameworks (MOFs) bonded to the amine group of the amine compound,
The amine compound is selected from N-methyl-1,3-diaminopropane or 1,3-diaminopentane,
An air purifier in which 90% or more of the carbon dioxide adsorbed to the carbon dioxide adsorbent is desorbed while the temperature of the carbon dioxide adsorbent is maintained at 70° C. or less according to the heat generated by the heater. delete 8. The method of claim 7,
The air purifier is a home appliance.

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