KR102077119B1 - Polyhydroxyamine-based carbon dioxide absorbent and method for absorbing/separating carbon dioxide using the same - Google Patents

Abstract

The present invention relates to a novel polyhydroxylamine-based carbon dioxide absorbent and a method for absorbing / separating carbon dioxide using the same, and is prepared by reacting an amine precursor, an aldehyde precursor, and an ammonium halide according to the present invention. Has excellent CO2 absorption ability, and the regeneration temperature is significantly lower than that of the conventional alkanolamine-based absorbents, which greatly reduces the total energy consumption required for the collection process. To prevent contamination.

Description

POLYHYDROXYAMINE-BASED CARBON DIOXIDE ABSORBENT AND METHOD FOR ABSORBING / SEPARATING CARBON DIOXIDE USING THE SAME}

The present invention relates to a polyamine hydroxide carbon dioxide absorbent and a method for absorbing / separating carbon tetrachloride using the same. More specifically, the present invention relates to a polyhydroxyamine-based carbon dioxide absorbent having excellent carbon dioxide absorption ability, absorption rate and reproducibility, and a method for absorbing / separating carbon dioxide using the same.

The most effective way to remove carbon dioxide from gases containing carbon dioxide, such as gas mixtures from hydrogen, steel and cement production processes, combustion flue gases from natural power plants and fossil fuels, and chemicals using amine-based aqueous solutions Absorption method. As the chemical absorbents, amine aqueous solutions such as monoethanolamine (MEA), diethanolamine (DEA), and the like have been studied the most, and these amine-based absorbents react with carbon dioxide to facilitate stable carbamate compounds. This is because these compounds are thermally decomposed into carbon dioxide and amine so that the alkanolamine absorbent can be regenerated. However, this process presents some serious problems, in particular the degradation of absorbents due to the generation and decomposition of by-products by impurities such as NOx, SOx and oxygen contained in combustion exhaust gases, resulting in device corrosion problems, carbon dioxide and The high thermal and chemical stability of the carbamate resulting from the reaction caused by excessive regeneration energy consumption due to high regeneration temperature of 120 ° C. or higher, excessive volatilization loss of alkanolamine at high regeneration temperature, consequent absorption of absorbents, Due to the low vapor pressure of the absorbent, the problem of polluting the separated carbon dioxide during the regeneration process has been pointed out as a disadvantage.

In order to compensate for the disadvantages of the amine-based aqueous solution absorbents, methods for physically absorbing carbon dioxide using organic solvents such as selexol, IFPexol, and NFM have been reported. The most important advantage of organic solvent absorbents is that much lower energy is required for carbon dioxide recovery and solvent regeneration, since carbon dioxide absorption is achieved only by the physical interaction between the absorbing solvent and carbon dioxide, not the chemical bonds as in amine-based aqueous solutions. In the case of using an aqueous amine-based absorbent, carbon dioxide recovery and absorbent regeneration require energy-intensive high temperature stripping, whereas in the case of physical absorption, carbon dioxide dissolved in the solvent simply by changing the pressure without increasing the temperature. Can be recovered.

However, when the physical absorbents separate carbon dioxide from the combustion gas having a low pressure, the physical absorbents exhibit much lower carbon dioxide absorption than the amine-based absorbents, and thus, the circulation rate of the absorbent must be increased, thereby requiring a larger equipment. Recently, new chemical absorbents with high thermal and chemical stability and low vapor pressure have been studied to overcome the disadvantages of the existing amine and organic solvent absorbents. In this regard, as a method for lowering the renewable energy of the chemical absorbent, a study has been attempted using an alkanolamine having a steric hindrance around the amine group of the alkanolamine as an absorbent. -Methyl-1-propanol (AMP). AMP has the advantage of 30% lower renewable energy than MEA because it forms bicarbonate compound that is more easily regenerated than carbamate when carbon dioxide is reacted, but carbon dioxide absorption rate is less than 50% of MEA. .

In order to increase the absorption rate of AMP, Mitsubishi Heavy Industries and Kansai Thermal Power Co., Ltd. jointly developed a new absorbent that added piperazine, a secondary cycloamine, to AMP and registered a patent (Japanese Patent No. 3197173). . However, the patent has a problem that precipitation occurs after carbon dioxide absorption due to the use of excess piperazine, and also has a disadvantage in that regeneration is difficult because piperazine and carbon dioxide react to form carbamate, which is a stable compound in addition to bicarbonate.

In addition, a method of using an alkali carbonate such as sodium carbonate or potassium carbonate as a carbon dioxide absorbent instead of a primary alkanolamine absorbent such as MEA is known, but the carbon dioxide absorption rate is slow. As one of the methods for increasing the rate of carbon dioxide absorption, International Publication No. WO2004-089512 A1 reports that the addition of piperazine or its derivatives to potassium carbonate greatly increases the rate of carbon dioxide absorption of potassium carbonate, but is precipitated by using carbonates. The formation problem still remains a challenge to be solved.

Japanese Patent No. 3197173 International Publication WO2004-089512 A1

An object of the present invention has a high durable carbon dioxide absorbent having a high carbon dioxide absorbing ability, and is capable of operating a carbon dioxide capture process at low regeneration temperature conditions, a method for preparing the same and a method for absorbing carbon dioxide using the same to solve the above problems To provide a way to separate them.

Exemplary embodiments of the present invention provides a polyhydroxyamine-based carbon dioxide absorbent, which is represented by the following Chemical Formula 1.

[Formula 1]

Halide is a halogen element, n is a repeating unit.

In exemplary embodiments of the present invention, a method for preparing a polyhydroxyamine-based carbon dioxide absorbent as described above, comprising reacting an amine precursor, an aldehyde precursor, and an ammonium halide; provides a method for preparing a polyhydroxyamine-based carbon dioxide absorbent. .

In exemplary embodiments of the present invention, by using an aqueous solution containing the aforementioned polyhydroxy amine-based carbon dioxide absorbent, absorbing carbon dioxide; provides a method for absorbing carbon dioxide.

In exemplary embodiments of the present invention, a method for absorbing carbon dioxide from a gas mixture including carbon dioxide using an aqueous solution including the polyamine hydroxide based carbon dioxide absorbent described above; And a second step of removing the carbon dioxide absorbed from the aqueous solution including the polyhydroxyamine-based carbon dioxide absorbent.

According to the present invention, the polyamine amine-based carbon dioxide absorbent not only has a high carbon dioxide absorption capacity and a fast absorption rate, but also a significantly lower absorbent regeneration temperature compared to a conventional absorbent, thereby greatly reducing the total energy consumption required for the absorption process. The initial absorption capacity can be almost maintained even after repeated absorption / removal of.

In addition, according to the present invention, it is possible to significantly reduce the overall energy consumption, so that the cost saving effect is expected, it can be applied to the entire industry that emits a large amount of carbon dioxide, and also applied to the field of high value-added organic compound synthesis using the collected carbon dioxide It is expected to be possible.

1 is an FT-IR spectrum of a carbon dioxide absorbent according to an embodiment of the present invention.
Figure 2 is a graph of carbon dioxide absorption according to the CO ₂ / N ₂ ratio (10% / 90% and 30% / 70%) of the carbon dioxide absorbent according to an embodiment of the present invention.
3 is a graph of carbon dioxide absorption / regeneration at 25/80 ° C. of a carbon dioxide absorbent according to an embodiment of the present invention.

Term Definition

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention disclosed in the text are illustrated for illustrative purposes only, and the embodiments of the present invention may be embodied in various forms and should not be construed as being limited to the embodiments described in the text. .

The present invention may be modified in various ways and may have various forms, and the embodiments are not intended to limit the present invention to a specific disclosed form, and all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention. It will be understood to include.

In the present specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding the other components unless otherwise stated.

Illustrative Of embodiments  Explanation

Hereinafter, exemplary embodiments of the present invention will be described in detail.

Polyamine Hydroxide Type  Carbon dioxide absorbent

Exemplary embodiments of the present invention, which is represented by the following formula (1), provides a polyhydroxyamine-based carbon dioxide absorbent.

[Formula 1]

Halide is a halogen element, n is a repeating unit.

Since the polyamine hydroxide carbon dioxide absorbent according to the present invention generates a bicarbonate (bicarbonate, HCO ₃ ) compound that is easily regenerated, as shown in the following [Scheme 1] when water is used as a solvent during carbon dioxide absorption / separation described below. Compared with the existing alkanolamine-based absorbents there is an advantage that can significantly lower the renewable energy.

Scheme 1

Therefore, when the polyamine amine-based carbon dioxide absorbent according to the present invention is used, carbamate is not formed even after carbon dioxide absorption, so that the absorbent can be regenerated even at a low temperature, and thus the energy of the overall absorption process can be reduced. In addition, corrosion and side reactions and absorbent loss problems derived from high regeneration temperatures can be greatly reduced.

In an exemplary embodiment, the poly-amine hydroxide dioxide FT-IR spectrum measurement of the absorber, 3200 to 3600cm ^-1 -OH peak which is located in the area, 1515 to -CNH peak located at 1570cm ^-1 region of 900 to 1300cm -CO- peak located in the ^-1 region, and -CN- located in the 1250 to 1360 cm ^-1 region.

In an exemplary embodiment, the halogen element may be Cl, I or Br, preferably I.

In an exemplary embodiment, n may be an integer from 1 to 9.

Polyamine Hydroxide Type  Carbon dioxide absorbent manufacturing method

In exemplary embodiments of the present invention, a method for preparing a polyhydroxy amine-based carbon dioxide absorbent, including reacting an amine precursor, an aldehyde precursor, and an ammonium halide; provides a method for preparing a polyamine-based carbon dioxide absorbent.

In an exemplary embodiment, the reaction may be a condensation reaction and may be reacted through a method such as stirring at an appropriate temperature and pH. Specifically, the reaction may be stirred for 1 to 3 hours while maintaining the pH at 2 to 5 at a temperature of 60 to 90 ° C.

In an exemplary embodiment, the amine precursor is urea, melamine, cyanamide, dicyandiamide, guanidine, biguanidine, guanylurea And at least one selected from the group consisting of polycyclic guanidine, and preferably urea.

In an exemplary embodiment, the aldehyde precursor is formaldehyde, acetaldehyde, propionaldehyde, butylaldehyde, benzaldehyde, glutaraldehyde, glyoxal, glyoxal, malon It may be one or more selected from the group consisting of dialdehyde (malondialdehyde), succinic aldehyde (succindialdehyde), and phthalaldehyde (phthalaldehyde), preferably glyoxal.

In an exemplary embodiment, the ammonium halide may be one or more selected from the group consisting of NH ₄ Cl, NH ₄ I, and NH ₄ Br, preferably NH ₄ I.

In addition, in order to manufacture the polyhydroxylamine-based carbon dioxide absorbent, an amine compound, a stabilizer and a molecular weight modifier may be added in the manufacturing process. For example, the amine compound may be hydroxyl amine or the like, and may include isopropyl alcohol as the stabilizer and the molecular weight regulator.

CO2 Absorption Method

In exemplary embodiments of the present invention, a method of absorbing carbon dioxide, comprising: absorbing carbon dioxide using an aqueous solution including the polyamine hydroxide-based carbon dioxide absorbent described above.

As described above, since the polyhydroxylamine-based carbon dioxide absorbent generates bicarbonate (HCO ₃ ) compounds that are easily regenerated by using water as a solvent, the renewable energy can be significantly lower than that of the conventional alkanolamine-based absorbents. Compared with other organic solvents, there is an advantage in that the handling and the price are lower.

In an exemplary embodiment, the content of the polyhydroxylamine-based carbon dioxide absorbent in the aqueous solution may be 1 to 99 parts by weight, and preferably 3 to 90 parts by weight based on 100 parts by weight of water. When the weight part is less than 1, the carbon dioxide absorption capacity may be lowered, and when the weight part is more than 99 parts by weight, the viscosity may be high and the absorption capacity may be reduced.

CO2 Separation Method

In exemplary embodiments of the present invention, a carbon dioxide separation method comprising: a first step of absorbing carbon dioxide from a gas mixture including carbon dioxide by using an aqueous solution including the polyamine hydroxide based carbon dioxide absorbent described above; And a second step of removing the carbon dioxide absorbed from the aqueous solution including the polyhydroxyamine-based carbon dioxide absorbent.

Types of gas mixtures containing carbon dioxide include chemical gases, power plants, steel companies, cement plants, exhaust gases, natural gas, sewage treatment plant biogas, and the like.

In an exemplary embodiment, the content of the polyhydroxy amine-based carbon dioxide absorbent in the aqueous solution may be 1 to 99 parts by weight based on 100 parts by weight of water.

In an exemplary embodiment, the absorption temperature of the first step may be 10 to 60 ° C, for example 15 to 50 ° C, preferably 20 to 40 ° C. If the absorption temperature exceeds 60 ℃ desorption proceeds at the same time because the amount of carbon dioxide absorption is reduced, if the absorption temperature is less than 10 ℃ because it requires an additional refrigeration equipment to lower the temperature, causing economic problems. .

In an exemplary embodiment, the absorption pressure of the first step may be atmospheric pressure to 50 atm, for example, atmospheric pressure to 40 atm, and preferably at atmospheric pressure to 30 atm. This is because the pressure of exhaust gas is atmospheric pressure, so absorption is also performed at normal pressure, and if the absorption pressure exceeds 50 atm, the amount of absorption may increase rapidly, but it is necessary to add additional equipment and compressor to increase the pressure, thereby lowering economic efficiency. do.

In an exemplary embodiment, the stripping temperature of the second step may be 60 to 120 ° C, for example 65 to 100 ° C, preferably 70 to 90 ° C. This is because when the stripping temperature is less than 60 ° C., the stripping does not proceed and when the stripping temperature exceeds 100 ° C., there is no significant difference from the temperature using the existing absorbent.

In an exemplary embodiment, the stripping pressure of the second step may be atmospheric pressure. Removal is difficult to proceed at high pressure, which is required to increase the vapor pressure of the water to maintain such a high pressure, which requires a high temperature and economic efficiency. Therefore, stripping is preferably performed at normal pressure.

In the term used in the specification of the present invention, "atmospheric pressure" means 1 atmosphere as "atmospheric pressure".

Hereinafter, specific embodiments according to exemplary embodiments of the present invention will be described in more detail. However, the present invention is not limited to the following examples, and various forms of embodiments can be implemented within the scope of the appended claims, and the following examples are only common in the art while making the disclosure of the present invention complete. It is to be understood that the invention is intended to facilitate the practice of the invention.

Example  : Polyamine Hydroxide Type  Carbon dioxide absorbent manufacturers

In a three-necked flask equipped with a thermometer, a reflux condenser, and a dropping device, 3.6 g of urea, 2.2 g of ammonium iodide, and 5.2 g of glyoxal were added, followed by stirring at a reaction temperature of 75 ° C. and pH 3 for 2 hours. Thereafter, 0.5 g of hydroxyl amine as an amine compound, 1 g of isopropyl alcohol as a stabilizer and a molecular weight modifier, and 5.2 g of glyoxal were added dropwise over 1 hour through a dropping device to condensation reaction.

The NMR analysis results of the prepared polyamine hydroxide carbon dioxide absorbent were as follows.

1 H-NMR (400 MHz, D2O) δ 4.80 (s, 2H), 4.79-4.29 (m)

13 C-NMR (100 MHz, D 2 O) δ 71.93.

Experimental Example

Experimental Example  One: Polyamine Hydroxide Type  FT-IR Spectrum Analysis of Carbon Dioxide Absorbers

The FT-IR spectrum analysis was performed on the polyamine hydroxide carbon dioxide absorbent prepared in Example 1. The result is as shown in FIG. 1, the 3200 to 3600cm ^-1 -OH peak which is located in the area, 1515 to -CNH peak located at 1570cm ^-1 region of 900 to 1300cm ^-1 -CO- peak located in the area, from 1250 to 1360cm ^{- It} was confirmed that -CN- located in region ¹ appeared.

Experimental Example  2: according to carbon dioxide / nitrogen ratio Polyamine Hydroxide Type  Carbon dioxide absorbent Absorption

In order to compare the carbon dioxide absorption capacity of the aqueous solution containing 10 parts by weight of the carbon dioxide absorbent prepared in Example 1 with respect to 100 parts by weight of water, the synthesis gas (carbon dioxide / nitrogen 10% / 90%, 30% / 70%) at room temperature and atmospheric pressure, injected into a 100ml aqueous solution at a rate of 30ml / min to measure the total amount and rate of carbon dioxide absorption, it is shown in Figure 2.

Referring to FIG. 2, it can be seen that carbon dioxide mixed with nitrogen in various ratios can be separated.

Experimental Example  3: according to temperature Polyamine Hydroxide Type  Absorption of Carbon Dioxide Absorbent / Playback (removal) ability

A rate of 30 ml / min of synthetic gas (carbon dioxide / nitrogen 10% / 90%) simulating actual L power plant and steel mill exhaust gas in 100 ml of an aqueous solution containing 10 parts by weight of the carbon dioxide absorbent prepared in Example 1 based on 100 parts by weight of water Injected into a temperature, the total amount and rate of carbon dioxide absorption at atmospheric pressure were measured while changing the temperature to 25 ℃ / 80 ℃, it is shown in FIG.

As can be seen in Figure 3, according to the present invention by using an aqueous solution containing a polyhydroxylamine-based carbon dioxide absorbent, by removing the carbon dioxide from the carbon dioxide absorbent (regeneration) only by temperature control without any other process conditions, You can confirm that you can play. In addition, carbon dioxide can be absorbed / regenerated (removed) even at a temperature (25/80 ° C) that is relatively lower than the absorption / removal condition of a commercially available akanolamine-based carbon dioxide absorber (25/120 ° C). You can check it.

Claims (17)

As a polyamine hydroxide type carbon dioxide absorbent,
The polyamine hydroxide carbon dioxide absorbent is represented by the following formula (1),
Polyamine hydroxide based carbon dioxide absorbent, which reacts directly with carbon dioxide:
[Formula 1]

Halide is a halogen element, n is a repeating unit. The method of claim 1,
When measuring the FT-IR spectrum of the polyamine hydroxide carbon dioxide absorbent,
Positioned -CO- peak, from 1250 to 1360cm ^-1 region located -CNH peak, 900 to 1300cm ^-1 region located -OH peaks, 1515, 1570cm ^-1 to a region located on the 3200 to 3600cm ^-1 region, A polyamine amine type | system | group carbon dioxide absorbent which shows CN <->. The method of claim 1,
The halogen element is a polyamine amine-based carbon dioxide absorbent, characterized in that Cl, I or Br. The method of claim 1,
N is an integer of 1 to 9 polyamine amine-based carbon dioxide absorbent. As a method for producing a polyamine hydroxide carbon dioxide absorbent according to any one of claims 1 to 4,
Reacting an amine precursor, an aldehyde precursor and an ammonium halide; polyamine amine-based carbon dioxide absorbent manufacturing method comprising a. The method of claim 5,
The reaction is a polyamine amine-based carbon dioxide absorbent manufacturing method, characterized in that the condensation reaction. The method of claim 5,
The amine precursors include urea, melamine, cyanamide, dicyandiamide, guanidine, biguanidine, guanylurea, and polycyclic guanidine. (Polycyclic guanidine) polyamine amine-based carbon dioxide absorbent production method characterized in that at least one member selected from the group consisting of. The method of claim 5,
The aldehyde precursor is formaldehyde (acetaldehyde), acetaldehyde (acetaldehyde), propionaldehyde (propionaldehyde), butylaldehyde (butylaldehyde), benzaldehyde, glutaraldehyde (glutaraldehyde), glyoxal (glyoxal), malondialdehyde (malondialdehyde) A method for producing a polyhydroxyamine based carbon dioxide absorbent, characterized in that at least one selected from the group consisting of succinic aldehyde (succindialdehyde) and phthalaldehyde (phthalaldehyde). The method of claim 5,
The ammonium halide is a method for producing a polyamine amine-based carbon dioxide absorbent, characterized in that at least one selected from the group consisting of NH ₄ Cl, NH ₄ I, and NH ₄ Br. As a carbon dioxide absorption method,
A method of absorbing carbon dioxide, comprising: absorbing carbon dioxide using an aqueous solution containing the polyamine hydroxide based carbon dioxide absorbent according to any one of claims 1 to 4. The method of claim 10,
The content of the polyamine amine-based carbon dioxide absorbent in the aqueous solution is 1 to 99 parts by weight based on 100 parts by weight of water. As a carbon dioxide separation method,
A first step of absorbing carbon dioxide from a gas mixture comprising carbon dioxide by using an aqueous solution containing the polyamine hydroxide carbon dioxide absorbent according to any one of claims 1 to 4; And
And a second step of removing the carbon dioxide absorbed from the aqueous solution including the polyhydroxyamine-based carbon dioxide absorbent. The method of claim 12,
The content of the polyhydroxy amine-based carbon dioxide absorbent in the aqueous solution is 1 to 99 parts by weight based on 100 parts by weight of water. The method of claim 12,
Carbon dioxide separation method, characterized in that the absorption temperature of the first step is 10 to 60 ℃. The method of claim 12,
The absorption pressure of the first step is carbon dioxide separation method, characterized in that the atmospheric pressure to 50 atm. The method of claim 12,
The stripping temperature of the second step is 60 to 120 ℃ characterized in that the carbon dioxide separation method. The method of claim 12,
The stripping pressure of the second step is a carbon dioxide separation method, characterized in that the normal pressure.

Images