KR101383762B1 - Carbon Dioxide Capture Sorbent and Method for Carbon Dioxide Capture - Google Patents

Abstract

The present invention reacts hydrazine and its derivatives with a gas containing carbon dioxide to chemically bond carbon dioxide to hydrazine and its derivatives in a ratio of 1: 1 to 2: 1. It provides a method that can desorb carbon dioxide from the combined material again with less energy.
In addition, since there is little decomposition of the absorbent during carbon dioxide absorption and desorption, it provides a possibility as a very efficient and stable adsorbent.

Description

Carbon Dioxide Capture Sorbent and Method for Carbon Dioxide Capture

The present invention relates to a carbon dioxide absorbent that is easy to collect due to high reactivity with carbon dioxide and easy to desorption of the captured carbon dioxide, and more particularly, has excellent thermal stability, large molar absorption capacity, and high carbon dioxide absorption ability and high regeneration at high pressure. It relates to a carbon dioxide absorbent.

Recently, due to rapid climate change, the seriousness of global warming has begun to be recognized around the world, and both developed and developing countries are struggling to come up with measures to reduce greenhouse gas emissions. In particular, as CO ₂ is regarded as a major cause of global warming, developed countries are trying to minimize CO ₂ emissions through international agreements. In this international movement, research on the development of fuels with high efficiency and low CO2 emissions using the same fossil fuel is being conducted. On the other hand, carbon dioxide from facilities such as existing plants and power plants using fossil fuels is being researched. We continue to conduct environmentally friendly research and development to capture and reuse carbon dioxide efficiently.

The collection methods for trapping carbon dioxide can be classified into chemical absorption method using liquid absorbent, physical adsorption method using solid material, and separation method using membrane. All these methods are commercially developed and used in actual processes have. Among them, the chemical absorption method using a liquid absorbent is widely used to capture carbon dioxide from exhaust gases, mainly from power plants and industrial facilities, which have a low carbon dioxide concentration and a large capacity. In particular, the chemical absorption method shows a high collection efficiency even at low emission concentrations where the carbon dioxide volume ratio is less than 20%. Therefore, it is considered to be an excellent collection method in terms of economy and process application method compared to other capture methods.

The process of using alkanol-amines as a liquid absorbent to capture carbon dioxide has been in use since the 1930s. Alkanol-amines have two functional groups at their ends. One is a hydrophilic hydroxy (-OH) group and the other is an amino (-NH ₂ , -NHR, -NR ₂ ) group that can bind to carbon dioxide.The characteristics of these two functional groups make it easy to capture carbon dioxide in aqueous solution. It is known to be the best compound. Since the process of using tri-ethanol-amine as the alkanol amine absorber for the first time, mono-ethanol-amine (MEA), di-ethanol-amine (DEA) Many amines, such as 2-methyl amino ethanol, di-isopropyl amine, piperazine and 2-piperidine-methanol A series of compounds has been developed. Among them, mono ethanol amine (MEA) and diethanol amine (DEA) are the most widely used because of the fast reaction rate with carbon dioxide. These absorbents are generally used in the form of an aqueous solution mixed with water having a concentration of 20 to 40% by weight. The aqueous amine solution has a high affinity with carbon dioxide, so that carbon dioxide contained in the exhaust gas which is burned out can be easily collected, and the amine absorbent containing carbon dioxide is heated in the reaction vessel to separate the original amine absorbent and carbon dioxide. The separated carbon dioxide is stored in another tank, and the amine absorbent solution is sent to the original carbon dioxide capture tank through a heat exchanger, and then recycled to separate and recover the carbon dioxide in the exhaust gas.

Carbon dioxide capture by alkanol amines is limited to a maximum of ₂ molar CO ₂ absorption capacity of 1 mole per 2 moles of alkanol amine. That is, one mole is needed to react with carbon dioxide to form carbamate, and one mole is used to capture the protons released from the carboxylic acid action of the carbamate. Even in the case of the most widely used mono ethanol amine (MEA), the ratio of mole of CO _{2 to} mole of amine is as small as 0.5, and the molar absorption capacity is low for economical carbon dioxide capture. Development of materials close to 1.0 is needed.

In addition to these fundamental problems with alkanol amines such as MEA and DEA, current processes using them as absorbents are regeneration processes that separate the two after capture because the amine functionality of MEA and DEA is strongly chemically bonded to C0 ₂ . At high temperatures, ie high energy is required.

A bigger problem is the degradation of absorbents such as MEA and DEA during this high temperature regeneration process, resulting in a drastic decrease in absorbent performance. Therefore, in order to maintain a constant amount of carbon dioxide absorbent during the entire process, it is necessary to continuously supply the absorbent as much as the amount of absorbed and consumed absorbent. In addition, MEA and DEA have high reactivity, so that the surrounding vessels are easily corroded and easily decomposed by the trace amount of oxygen contained in the exhaust gas.

Therefore, in order to efficiently capture carbon dioxide using the chemical absorption method, it is necessary to develop a new absorbent which has a high molar absorption capacity, low energy required for regeneration of the absorbent, and a thermally stable absorbent to minimize the additional supply. . As a way to compensate for the drawbacks of these MEA and DEA absorbents, the possibility of using ionic liquids with high thermal stability and low corrosion resistance and low volatility as new absorbents to replace alkanol amines can be found. Many studies are being done for this purpose. However, ionic liquids may be a good alternative in terms of the ability to selectively absorb carbon dioxide by controlling the capture temperature, but the cost is high and the CO2 absorption capacity is very low at room temperature, thus capturing carbon dioxide in the exhaust gas from large-capacity plants. It is known that the ionic liquid developed so far is difficult to utilize.

The present inventors have been derived by the present inventors in order to solve the disadvantages of the alkanol amine absorbents, when using the hydrazine as a liquid absorbent at room temperature and normal pressure through the present invention, the existing alkanol amines such as MEA and DEA It has been found that the drawbacks of absorbents, such as low molar absorption capacity, corrosiveness, and thermal safety, can be solved, and the additional energy in the regeneration process is very advantageous for process design. It was completed.

Accordingly, an object of the present invention is to provide a method for preparing hydrazinium carboxylate by adsorbing carbon dioxide and hydrazine derivatives.

Another object of the present invention to provide a carbon dioxide adsorbent comprising a hydrazine derivative as an active ingredient.

Other objects and advantages of the present invention will become more apparent from the following detailed description of the invention, claims and drawings.

According to one aspect of the present invention,

Provided is a method of adsorbing a mixed gas containing carbon dioxide and a hydrazine derivative represented by the following Chemical Formula 1.

[Chemical Formula 1]

R ₁ and R ₂ are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms or an alcohol group having 2 to 4 carbon atoms, an ether group, or an alcohol ether group.

According to another aspect of the present invention,

(i) placing a hydrazine derivative represented by Chemical Formula 1 into a reactor and reacting with a mixed gas containing carbon dioxide at a temperature of 0-100 ° C. under a pressure of 0.5-30 MPa to produce a solid; And

(ii) washing the resulting solid with a solvent and drying

It provides a method for producing a hydrazinium carboxylate comprising.

[Chemical Formula 1]

R ₁ and R ₂ are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms or an alcohol group having 2 to 4 carbon atoms, an ether group, or an alcohol ether group.

The present invention was derived to solve problems such as low molar absorption capacity, easy corrosion, and thermal instability, which are disadvantages of the conventional alkanol amine absorbent, and the above problem is introduced by introducing hydrazine as a carbon dioxide absorbent at room temperature and liquid. There is a technical problem in solving them.

[Chemical Formula 1]

In order to achieve the above object, the present invention provides a carbon dioxide capture absorbent comprising a hydrazine compound of the formula (1). Wherein R 1 to R 2 are independently hydrogen or alkyl having 1 to 4 carbon atoms or alcohol or ether having 2 to 4 carbon atoms or an alcohol ether, preferably hydrogen or lower alkyl having 1 to 3 carbon atoms and lower alcohol having 2 to 3 carbon atoms . 1 briefly summarizes the reaction process for carbon dioxide adsorption / desorption by the hydrazine and its derivatives of the present invention.

In the present invention, the absorbent according to the present invention is a hydrazine and a derivative thereof having a structure of Formula 1 as an absorbent as shown in Figure 1 described above using a pure compound, or water, alcohol and ether, or a mixture thereof Can be used. In addition, small amounts of amine accelerators may be mixed in some cases. Accelerators not only increase the rate of carbon dioxide absorption, but also facilitate the separation of carbon dioxide. It is believed that it is preferable to use the solution in the concentration of the absorbent in the range of 5 to 65% (w / v). When the concentration of the absorbent is less than 5%, the rate of reaction with carbon dioxide is very slow. If the concentration is 65% or more, the amount of carbon dioxide absorbed is large and the absorption rate is high, but a large amount of absorbent may be used, which may not be effective.

In the present invention, the capture of carbon dioxide is carried out in the range of the temperature of the absorbent is -20 to 180 ℃, preferably 0 to 100 ℃. Absorption of carbon dioxide is carried out at a pressure, in the range of about 0.3 to 100 MPa, particularly preferably on the order of 0.5 to 30 MPa. Preferred capture of carbon dioxide sinks into the solution as a white precipitate, forming a compound between the absorbent hydrazine and carbon dioxide.

Features and effects of the present invention are as follows.

The hydrazine absorbent according to the present invention has remarkably improved problems such as low molar absorption capacity, easy corrosion, and thermal instability, which are disadvantages of conventional alkanol amine absorbers such as mono ethanol amine. The molar absorption capacity can be increased to twice the capacity of mono ethanol amine, and in the case of aqueous hydrazine solution, there is almost no corrosiveness, so that the reaction vessel is not easily corroded, and the thermal hydrazine is very stable and does not easily decompose even at a high temperature of about 100 ° C. .

In addition, when the exhaust gas containing carbon dioxide is made into a high pressure in the range of 0.3-100 MPa and blown into an aqueous hydrazine solution, it is easily converted into a solid powder (hydrazinium carboxylate), thereby greatly reducing the time and energy required to capture carbon dioxide. have. In addition, the solid powder captured carbon dioxide can be easily separated from the water. The collected solid powder (hydrazinium carboxylate, NH ₃ ⁺ NHCO ₂ ⁻ ) is easily separated into hydrazine (NH ₂ NH ₂ ) and carbon dioxide (CO ₂ ) in water without additional energy supply. This method, which can efficiently absorb and separate carbon dioxide by using hydrazine, is a technology that has not been disclosed in the past and is a breakthrough technology.

The hydrazine absorbent developed through the present invention is 1) molar absorption capacity is more than twice the amine absorbent compared to the conventional alkanol amine absorbent, 2) weak corrosive, 3) thermally stable, 4) capture carbon dioxide The resulting compound is in a stable solid state in water, so it is easy to separate, and 5) the separation and recovery process is simple, so that no additional energy supply is required, thus providing an eco-friendly and economical operation process of the facility.

1 is a reaction diagram showing a carbon dioxide absorption and desorption process by the hydrazine and its derivatives in the present invention.

The present invention provides a carbon dioxide absorbent having a high absorption capacity, high absorption capacity, low corrosion, and thermal stability, which is easy to collect and easily desorbed from the exhaust gas emitted from a power plant or an industrial facility. To provide.

Hydrazine (NH ₂ NH ₂ ) is an amine-based compound such as mono ethanol amine (HOCH ₂ CH ₂ NH ₂ ) and is a transparent liquid at room temperature. The molecular weight of hydrazine (32.05) is about half as small as that of mono ethanol amine (61.08), but its melting point and density are similar to that of mono ethanol amine. However, the boiling point is higher in mono ethanol amine (170 ° C.) than hydrazine (114 ° C.), and the base strength is also stronger in mono ethanol amine (p K _a = 9.50) than hydrazine (p K _a = 8.10). Based on the properties of the base alone, mono-ethanol amines are expected to capture carbon dioxide better than hydrazine. However, the strong absorption of the mono ethanol amine may require a high energy in the process of separating the carbon dioxide after the adsorption of carbon dioxide may be a problem.

The advantage of using hydrazine as a carbon dioxide absorber is that it can be combined 1: 1 with carbon dioxide. These results suggest that the present inventors have formed a stable solid powder when hydrazine reacts with high-pressure carbon dioxide through previous studies, and the solid is hydrazinium carboxylate (NH) in which hydrazine and carbon dioxide are combined in a 1: 1 ratio. was initially identified as that) ^- ₃ ⁺ NHCO _2. As a result, one mole of hydrazine can capture one mole of CO ₂ , and the maximum value of the molar absorption capacity ratio of hydrazine is 1.0. In contrast, the monoethanolamine currently in use has a maximum molar absorption capacity of only 0.5. In addition, carbon dioxide separation may be easier because the affinity with carbon dioxide is relatively weak compared to mono ethanol amine.

By introducing hydrazine, a liquid at room temperature and atmospheric pressure, into a carbon dioxide absorbent, the molar absorption capacity is almost twice that of a commercially available monoethanolamine absorbent, and is almost noncorrosive. A very stable carbon dioxide absorbent.

[Reaction Scheme 1]

[Reaction Scheme 2]

Scheme 1 relates to the capture of carbon dioxide by the hydrazine-based compound of the present invention, Scheme 2 is a reaction scheme for the capture of carbon dioxide using a compound of the known amine series. In Scheme 2, since one molecule of carbon dioxide is trapped in two molecules of the amine compound, up to 0.5 molecules of carbon dioxide are collected in one molecule of amine. However, the hydrazine-based compounds proposed in the present invention can be seen that since one molecule of hardazine traps one molecule of carbon dioxide, the carbon dioxide collection efficiency is doubled.

In addition, it was also confirmed that by performing the reverse reaction of Scheme 1, carbon dioxide can be desorbed with very little energy (see FIG. 1). That is, when the resulting solid is separated from the solvent, and then a solvent containing water is added again, hydrazine and its derivatives are converted into the original structure of Chemical Formula 1 while generating carbon dioxide. This process was carried out from room temperature to 80 ^o C, it was confirmed that the desorption of carbon dioxide as the temperature increases.

When the hydrazine derivative contains an active ingredient using the carbon dioxide capture method, it can be used as an absorbent to capture carbon dioxide. In this case, alcohols having 1 to 4 carbon atoms, diols having 2 to 8 carbon atoms (glycol), and ethers having 2 to 8 carbon atoms may be used alone, mixed with them, mixed with water, or water. When used together with their mixtures, carbon dioxide can be more effectively adsorbed or desorbed.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, it should be understood that the following Examples are intended to illustrate the present invention and not to limit the present invention.

Example  One :

5.0 g of a solution of hydrazine hydrate with a moisture content of about 36% by weight is placed in a 300 mL Parr reactor and the pressure of the carbon dioxide and the temperature of the reactor are adjusted to produce hydrazinium carboxylate (H ₃ N ⁺ NHCO _2- ^). , HC) was prepared. The pressure of carbon dioxide was 7.4 MPa and the temperature was reacted for 5 hours at 50 ° C. After the reaction, the resulting carbon dioxide was blown off with gas and the remaining solid was washed 5 times with 20 mL of methanol and dried in vacuo for 3 hours to obtain a hydrazinium carboxylate solid. The yield of H ₃ N ⁺ NHCO ₂ ^- obtained on the basis of the used hydrazine hydrate was ˜100% (˜7.59 g). That means that the carbon dioxide capture rate per molecule of hydrazine is ~ 100%.

Elemental analysis (unit%) for the product H ₃ N ⁺ NHCO ₂ ^-

Elements (calculated, experimental): C (15.74, 15.75), H (5.33, 5.31), N (36.84, 36.70)

MS (EI +) m / z = 32 [M] +, 31, 29, 17, 15

compare Example  One :

12.2 g of monoethanol amine (MEA) was reacted with carbon dioxide without a solvent, the rest of which was the same as in Example 1. The compound obtained after the reaction was analyzed as such without washing process, the analysis result 2-hydroxy-ethanaminium 2-hydroxy -ethylcarbamate - was a compound known as _{(HOCH 2 CH 2 NHCO 2 H} 3 N + CH 2 CH 2 OH), with The yield obtained on the basis of MEA was ˜94% (15.6 g). This means that the carbon dioxide capture rate per molecule of MEA is up to 47%.

Example  2 :

3 mL of ethanol was used as a solvent, and the rest was carried out as in Example 1 to obtain a solid, which was not washed separately.

The yield of H ₃ N ⁺ NHCO ₂ ^- obtained based on the used hydrazine hydrate was greater than 99% (7.52 g). That is, the carbon dioxide capture rate per molecule of hydrazine is 99% or more. The results of the analysis were the same as those in Example 1.

Example  3:

3 mL of methanol was used as a solvent, and the rest was carried out as in Example 1 to obtain a solid, and no separate washing was performed.

The yield of H ₃ N ⁺ NHCO ₂ ^- obtained based on the used hydrazine hydrate was greater than 99% (7.52 g). That is, the carbon dioxide capture rate per molecule of hydrazine is 99% or more. The results of the analysis were the same as those in Example 1.

Example  4 :

5 mL of ether was used as a solvent, and the rest was carried out as in Example 1 to obtain a solid, which was not washed separately.

The yield of H ₃ N ⁺ NHCO ₂ ^- obtained based on the used hydrazine hydrate was more than 98% (7.49 g). That is, the carbon dioxide capture rate per molecule of hydrazine is 98% or more. The results of the analysis were the same as those in Example 1.

Example  5:

2 mL of methanol / 2 mL of ether was used as a solvent, and the rest was carried out as in Example 1 to obtain a solid, and no separate washing was performed.

The yield of H ₃ N ⁺ NHCO ₂ ^- obtained based on the used hydrazine hydrate was more than 98% (7.50 g). That is, the carbon dioxide capture rate per molecule of hydrazine is 98% or more. The results of the analysis were the same as those in Example 1.

Example  6:

6.4 g of a hydrazine hydrate solution having a water content of about 50% by weight was reacted, and the rest was the same as in Example 1. The yield of H ₃ N ⁺ NHCO ₂ ^- obtained based on the used hydrazine hydrate was not less than 98% (7.50 g). That is, the carbon dioxide capture rate per molecule of hydrazine is 98% or more. The results of the analysis were the same as those in Example 1.

Example  7:

16.0 g of a hydrazine hydrate solution having a water content of about 80% by weight was reacted, and the rest was the same as in Example 1. The yield of H ₃ N ⁺ NHCO ₂ ^- obtained based on the used hydrazine hydrate was not less than 98% (7.45 g). That is, the carbon dioxide capture rate per molecule of hydrazine is 98% or more. The results of the analysis were the same as those in Example 1.

Example  8 :

20.0 g of a hydrazine hydrate solution having a water content of about 96% by weight was reacted, and the rest was the same as in Example 1. The yield of H ₃ N ⁺ NHCO ₂ ^- obtained based on the used hydrazine hydrate was not less than 98% (1.8 g). That is, the carbon dioxide capture rate per molecule of hydrazine is 98% or more. The results of the analysis were the same as those in Example 1.

Example  9:

The pressure of carbon dioxide was 3 MPa and the reaction time was 12 hours. The rest was the same as in Example 1. The yield of H ₃ N ⁺ NHCO ₂ ^- obtained based on the used hydrazine hydrate was not less than 98% (7.51 g). . That is, the carbon dioxide capture rate per molecule of hydrazine is 98% or more. The results of the analysis were the same as those in Example 1.

Example  10:

The pressure of carbon dioxide was 0.5 MPa, the reaction time was 12 hours, the temperature was 0 ^o C, 0.5 g of the hydrazine solution was used, and the rest was the same as in Example 1, H ₃ N ⁺ obtained based on the used hydrazine hydrate. The yield of NHCO ₂ ⁻ was not less than 98% (0.749 g). That is, the carbon dioxide capture rate per molecule of hydrazine is 98% or more. The results of the analysis were the same as those in Example 1.

compare Example  2 :

1.22 g of monoethanol amine (MEA) was used, the pressure of carbon dioxide was 0.5 MPa, the reaction time was 12 hours, the temperature was 0 ^o C, and the rest was performed in the same manner as in Comparative Example 1. The compound obtained through the reaction was a mixture of a compound known as 2-hydroxy-ethanaminium-2-hydroxy-ethylcarbamate and MEA, and the total mass of the obtained mixture was 1.43 g. That is, there was a mass increase of 0.21 g, which means that the carbon dioxide capture rate was ~ 23% based on the MEA used.

Example  11:

The reaction was carried out in the same manner as in Example 1 except that 50 g of dry ice, which was solid carbon dioxide, was used as a source of carbon dioxide. The yield of H ₃ N ⁺ NHCO ₂ ^- based on the hydrazine hydrate used was over 98%. That is, the capture rate of carbon dioxide per molecule of hydrazine is 98% or more. The analysis results were the same as in Example 1.

Example  12:

The reaction was carried out in the same manner as in Example 1, except that the reaction was completed using a mixed gas having a ratio of carbon dioxide and oxygen of 2: 1, that is, P (CO ₂ ) / P (O ₂ ) = 5.0 / 2.5, and a total pressure of 7.5 MPa. It was. The yield of H ₃ N ⁺ NHCO ₂ ^- obtained based on the used hydrazine hydrate was ~ 100%. That is, the carbon dioxide capture rate per molecule of hydrazine is ~ 100%, which means that the decomposition of hydrazine did not occur. The analysis results were the same as in Example 1.

Example  13:

The reaction was carried out in the same manner as in Example 11, but the reaction was completed at a ratio of carbon dioxide and oxygen of 1: 2, that is, P (CO ₂ ) / P (O ₂ ) = 2.5 / 5.0 and a total pressure of 7.5 MPa. Yield and analysis results were almost the same as in Example 1.

Example  14:

The reaction was carried out in the same manner as in Example 11 except that the ratio of carbon dioxide and oxygen was 1: 4, that is, P (CO ₂ ) / P (O ₂ ) = 10/40, and the total pressure was 5.0 MPa. Yield and analysis results were almost the same as in Example 1.

Example  15:

In the same manner as in Example 1, 4.60 g of 1-methyl hydrazine was used instead of hydrazine hydrate. The resulting powder is analyzed result by the general formula is 2-methyl-hydrazine carboxylic acid 2-methyl-hydrazine carboxylate jinyum ^- was a compound represented by (2-methyl hydrazinium carboxylate, ( CH 3) H 2 N + NHCO 2). The yield of (CH ₃ ) H ₂ N ⁺ NHCO ₂ ^- obtained on the basis of the used 1-methyl hydrazine was not less than 97% (8.74 g). This means that the carbon dioxide capture rate per molecule of methyl hydrazine is at least 97%. Elemental analysis of the product (CH ₃ ) H ₂ N ⁺ NHCO ₂ ^- in%

Elements (calculated, experimental): C (26.66, 26.57), H (6.71, 6.76), N (31.10, 30.96)

1 H NMR (400 MHz, CD ₃ OD, 27 ° C.) δ 4.96 (br s, 2H, —N H & —N ⁺ H ₂ ), 2.68 (br. S, 3H, CH ₃ ); _{13C NMR (100 MHz, CD 3} OD, 27 ℃) δ 38. 0 (C H 3), 160.1 (C = O).

Example  16:

In the same manner as in Example 1, 7.61 g of 2-hydrazinoethanol was used instead of hydrazine hydrate.

The powder analysis by the formula is 2- (2-hydroxyethyl) hydrazinium carboxylate , (HOCH 2 CH 2) H 2 N + NHCO 2 - was a compound represented by). The yield of (HOCH ₂ CH ₂ ) H ₂ N ⁺ NHCO ₂ ^- obtained on the basis of 2-hydrazinoethanol was over 95% (11.5 g). This means that the carbon dioxide capture rate per molecule of 2-hydrazinoethanol is 95% or more. Elemental analysis of the product (HOCH ₂ CH ₂ ) H ₂ N ⁺ NHCO ₂ ^- (%)

Elements (calculated, experimental): C (30.00, 29.57), H (6.71, 6.86), N (23.32, 23.71)

1 H NMR (400 MHz, CD ₃ OD, 27 ° C) δ 2.90 (br s, 2H, C H ₂ -N), 3.70 (br s, 2H, C H ₂ -OH), 4.98 (m, 3H, O H , -N H & -N ⁺ H ₂ ), 13 C NMR (100 MHz, CD ₃ OD, 27 ° C) δ 55.1 ( C H ₂ -N), 58.4 ( C H ₂ -O), 164.6 ( C = O) .

Example  17:

In the same manner as in Example 1, 6.01 g of 1,1-dimethyl hydrazine was used instead of hydrazine hydrate. The resulting powder has a formula elemental analysis results are 2,2-dimethyl-hydrazine carboxylate jinyum ^- was a compound represented by (2,2-dimethyl hydrazinium carboxylate, ( CH 3) 2 HN + NHCO 2). The yield of (CH ₃ ) ₂ HN ⁺ NHCO ₂ ^- obtained on the basis of 1,1-dimethyl hydrazine used was not less than 94% (9.78 g). This means that the capture rate of carbon dioxide per molecule of 1, 1-dimethyl hydrazine is 94% or more. Elemental analysis of the product (CH ₃ ) ₂ HN ⁺ NHCO ₂ ^- in%

Elements (calculated, experimental): C (34.61, 34.56), H (7.75, 7.78), N (26.91, 26.79)

1 H NMR (400 MHz, CD ₃ OD, 27 ° C) δ 2.47 (s, 6H, CH ₃ ), 4.92 (br s, 2H, —N H & —N ⁺ H ); _{13C NMR (100 MHz, CD 3} OD, 27 ℃) δ 49. 0 (br, C H 3), 160.1 (C = O).

Example  18:

Example 1 Solid jinyum Hydra-carboxylate obtained in ^{_{(hydrazinium carboxylate, H 3 N +}} NHCO 2 -, HC) 0.76 g were placed in a 10 mL flask was tightly sealed was added 1.8 g water. The mixture was stirred for 3 hours in a 30 ° C water bath. The mass of the solution remaining after carbon dioxide generation was 2.20 g, and the generated gaseous carbon dioxide was bubbling in a solution in which 1.71 g of barium hydroxide Ba (OH) 2 (10.0 mmol) was dissolved in 0.5 L of water. The resulting white precipitate was filtered through a filter, and water was removed using 10 mL of methanol solvent. This process was repeated three times to obtain 1.58 g of white precipitate, which was analyzed by XRD to confirm that the material was BaCO ₃ (Ba basis yield ~ 80%).

This scheme is shown below.

Ba (OH) ₂ + CO ₂ BaCO ₃ + H ₂ O

About 80% of the Hydra jinyum carboxylate from the ^results it can be seen that ^{_{(hydrazinium carboxylate, H 3 N +}} NHCO 2, HC) is converted into hydrazine hydrate loses carbon dioxide.

Example  19:

Reaction temperature was reacted at 80 degreeC for 1 hour, and the remainder is the same as that of Example 18. About 2.2 g of reaction solution and 1.93 g of BaCO ₃ were obtained. It can be seen that the conversion to ^{- (, HC hydrazinium carboxylate, H} 3 N + NHCO 2) hydrazine hydrate loses carbon dioxide results in almost 100% hydrazine jinyum carboxylate from.

Example  20:

3 g of methanol was used and the rest are the same as in Example 19.

The results were almost the same as in Example 19.

Example  21:

3 g of propanol was used and the rest is the same as in Example 19.

The results were almost the same as in Example 19.

Example  22:

3 g of ethylene glycol were used and the rest are the same as in Example 19.

The results were almost the same as in Example 19.

Example  23:

3 g of 1,4-butanediol were used and the remainder is the same as in Example 19.

The results were almost the same as in Example 19.

Example  24:

1.0 g of water and 1 g of methanol were used, the remainder being the same as in Example 19.

The results were almost the same as in Example 19.

Example  25:

1.0 g of water and 2 g of ethylene glycol were used, and the rest were the same as in Example 19.

The results were almost the same as in Example 19.

Example  26:

1 g of methanol and 2 g of ethylene glycol were used, and the rest were the same as in Example 19.

The results were almost the same as in Example 19.

Example  27:

1.0 g of water, 1 g of methanol and 1 g of ether were used and the remainder is the same as in Example 19. The results were almost the same as in Example 19.

Example  28:

2 g of methanol and 1 g of ether were used and the remainder is the same as in Example 19. The results were almost the same as in Example 19.

Claims (28)

A method of adsorbing a mixed gas containing carbon dioxide and a hydrazine derivative represented by the following Chemical Formula 1,
The hydrazine derivative is 40-50% by weight relative to the total adsorption compound, method:
[Chemical Formula 1]

R ₁ and R ₂ are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms or an alcohol group having 2 to 6 carbon atoms, an ether group, or an alcohol ether group.
(i) adding a hydrazine derivative represented by Chemical Formula 1 to a reactor and reacting with a mixed gas containing carbon dioxide at a temperature of −20 to 180 ° C. under a pressure of 0.5-30 MPa to generate a hydrazine and carbon dioxide adsorbate; And
(ii) washing the resulting solid with a solvent and drying
Including;
The hydrazine derivative is 40-50% by weight relative to the total adsorption compound,
How to prepare hydrazinium carboxylate:
[Chemical Formula 1]

R ₁ and R ₂ are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms or an alcohol group having 2 to 6 carbon atoms, an ether group, or an alcohol ether group.
delete The method of claim 1 or 2, wherein the hydrazine derivative is characterized in that the adsorbed by converting to water by adding together.
The method of claim 4 wherein the content of water in the hydrate is 35-95% by weight.
The method of claim 1 or 2, wherein the hydrazine derivative is characterized in that the adsorbed by the addition of alcohol having 1 to 4 carbon atoms.
The method of claim 6, wherein the alcohol having 1 to 4 carbon atoms is characterized in that the content of 35 to 95% by weight relative to the total solution.
The method of claim 1, wherein the hydrazine derivative is adsorbed by adding water and an alcohol having 1 to 4 carbon atoms together.
The method of claim 8, wherein the mixed solvent of water and an alcohol having 1 to 4 carbon atoms has a content of 35 to 95 wt% based on the total solution.
delete The method according to claim 1 or 2, wherein the hydrazine derivative is adsorbed by adding a diol having 2 to 8 carbon atoms together.
The method according to claim 11, wherein the diol having 2 to 8 carbon atoms is characterized in that the content of 35 to 95% by weight relative to the total solution.
The method of claim 1, wherein the hydrazine derivative is adsorbed by adding water and a diol having 2 to 8 carbon atoms together.
The method of claim 13, wherein the mixed solvent of water and a diol having 2 to 8 carbon atoms has a content of 35 to 95 wt% based on the total solution.
delete The method of claim 1 or 2, wherein the hydrazine derivative is characterized in that the adsorption by adding a C1-4 alcohol and C2-8 ether together.
The method according to claim 16, wherein the mixed solvent of the alcohol having 1 to 4 carbon atoms and the ether having 2 to 8 carbon atoms has a content of 35 to 95% by weight relative to the total solution.
delete The method of claim 1 or 2, wherein the hydrazine derivative is adsorbed by adding water, alcohol having 1 to 4 carbon atoms and ether having 2 to 8 carbon atoms together.
20. The method of claim 19, wherein the mixed solvent of water, an alcohol having 1 to 4 carbon atoms, and an ether having 2 to 8 carbon atoms is 35 to 95% by weight based on the total solution.
The method of claim 1 or 2, wherein the hydrazine derivative is characterized in that the adsorption by adding a C1-4 alcohol and a C2-8 diol together.
22. The method of claim 21, wherein the mixed solvent of the C1-4 alcohol and the C2-8 diol has a content of 35-95 wt% based on the total solution.
delete The method of claim 1 or 2, wherein the hydrazine derivative is adsorbed by adding water, alcohol having 1 to 4 carbon atoms and diol having 2 to 8 carbon atoms together.
The method of claim 24, wherein the mixed solvent of water, an alcohol having 1 to 4 carbon atoms, and a diol having 2 to 8 carbon atoms has a content of 35 to 95 wt% based on the total solution.
The method of claim 1 or 2, wherein the hydrazine derivative is adsorbed by adding water, diol having 2 to 8 carbon atoms and ether having 2 to 8 carbon atoms.
27. The method of claim 26, wherein the mixed solvent of water, a diol having 2 to 8 carbon atoms, and an ether having 2 to 8 carbon atoms is present in an amount of 35 to 95% by weight relative to the total solution.
Carbon dioxide adsorbent comprising a hydrazine derivative of the general formula (1) according to claim 1 or 2 as an active ingredient:
[Chemical Formula 1]

;
R ₁ and R ₂ are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms or an alcohol group having 2 to 6 carbon atoms, an ether group, or an alcohol ether group.

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