KR20220120279A - Method for preparing spherical amine-based carbon dioxide adsorbent by one-pot synthesis - Google Patents

Abstract

The present invention relates to a one-pot preparing method of a spherical amine-based carbon dioxide adsorbent, and more particularly, to a one-pot preparing method of a spherical amine-based carbon dioxide adsorbent which exhibits significant advantages in mass production as a preparing process is very simplified by synthesizing a solution, in which an amine compound and a carrier raw material are mixed, through spray drying once. The spherical amine-based carbon dioxide adsorbent according to the present invention is synthesized in one-pot and goes through a process of spray drying once. In the case of a conventional amine-based carbon dioxide adsorbent, processes for preparing the amine compound and the carrier are respectively required in a grafting method and an impregnating method, which are representative methods of carrying the amine compound on the carrier. The general process goes through complicated processes, such as a process of grafting and impregnating an amine material into the carrier, comprising a process of drying and firing for preparing the carrier, and a drying process thereafter, which is quite disadvantageous in terms of mass production. On the other hand, the one-pot amine-based spherical amine-based carbon dioxide adsorbent according to the present invention is prepared by mixing the amine compound and the carrier raw material in one-pot and spray drying only once to have a significant advantage in terms of mass production.

Description

One-pot manufacturing method of a spherical amine-based carbon dioxide adsorbent {Method for preparing spherical amine-based carbon dioxide adsorbent by one-pot synthesis}

The present invention relates to a one-pot manufacturing method of a spherical amine-based carbon dioxide adsorbent, and more particularly, by synthesizing a solution in which an amine compound and a carrier raw material are mixed through one spray drying, the manufacturing process is greatly simplified and mass production It relates to a method for producing a spherical amine-based carbon dioxide adsorbent that exhibits significant advantages in

Carbon Dioxide Capture & Storage (CCS) technology captures and stores _{CO 2 emitted} from mass emission sources such as power plants and chemical processes due to the use of fossil fuels so as not to be emitted into the atmosphere. Although there is growing concern that human survival will be threatened by global warming caused by greenhouse gases, the demand for fossil fuels is still expected to increase according to the global energy consumption structure forecast. Therefore, it is essential to develop CCS technology to use fossil fuels while minimizing carbon dioxide emissions.

When carbon dioxide is captured, carbon dioxide must be separated from carbon dioxide exhaust gas and then concentrated to a high concentration. There are three types of these capture technologies: post-combustion capture, pre-combustion capture, and oxygen-combustion capture. Among them, the technology that can be easily applied to the current process system and is the closest to commercialization is the post-combustion capture technology. Among the post-combustion capture technologies, the most widely used benchmark technology is the wet absorption method using an aqueous amine solution such as monoethanolamine (MEA). It is a method of separating high concentration of carbon dioxide by regenerating the solution at high temperature. The reason this method is currently most widely used is because of the advantage that the amine aqueous solution has high carbon dioxide selectivity and easy heat exchange. However, this method has disadvantages such as corrosion of equipment and evaporation of amines. In order to overcome this disadvantage, a collection technology using a dry adsorbent rather than a wet absorption method is attracting attention. It is considered as an alternative technology.

In the amine-based dry adsorbent, carbon dioxide is adsorbed through the chemical bond between the amine and carbon dioxide in the adsorbent, similar to the wet absorption method using an aqueous amine solution. As for the carbon dioxide dry adsorbent, a type of adsorbent in which an amine is supported on a porous carrier has been studied. Typically, an adsorbent (Xu, Xu, X., Song, C., Andresen J. M., Miller, B. G., Scaroni, A. W., "Preparation and Characterization of Novel CO2 Molecular Basket Adsorbents Based on Polymer-modified Mesoporous Molecular Sieve MCM-41", Micro. Meso. Mater., 62 , 29-45 (2003)), an adsorbent prepared using hollow sphere granular mesoporous silica as a polyethyleneimine carrier (Qi, G., Wang, Y., Estevez, L., Duan, X) ., Anako, N., Park, A. A., Li, W., Jones, C. W., Giannelis, E. P., "High efficiency nanocomposite sorbents for CO2 capture based on amine-functionalized mesoporous capsules", Energy & Environmental Science 4,444-452 (2011) )), analysis of carbon dioxide adsorption capacity and adsorption rate for an adsorbent loaded with polyethyleneimine on MCF (Mesocellualr Silica Foam) with a very large mesopore volume (Zhang, H., Goeppert, A., Czaun, M., SuryaPrakash, G. K. , Olah, G. A., "CO2 capture on easily regenerable hybrid adsorbents based on polyamines and mesocellular silica foam. Effect of pore volume of the support and polyamine molecul ar weight", Royal Society of Chemistry 4,19403-19417 (2014)). In such a carbon dioxide dry adsorbent research, a representative method of supporting an amine on a carrier is a grafting reaction using a functional group such as a hydroxyl group on the surface of the carrier or a method of impregnating an amine material in the pores of the carrier.

However, when the amine compound is supported on the support in this way, a process for preparing the amine compound and the support is required, respectively. Therefore, the process undergoes a complex process such as grafting, impregnating, and drying the amine material to the support, including drying and firing processes for manufacturing the support, which increases production cost and reduces productivity. act as a factor Therefore, in order to increase the ease of mass production of the adsorbent, it is necessary to develop a process for producing the adsorbent as simplified as possible.

Accordingly, the present inventors have made a diligent effort to develop a simplified adsorbent production process as possible to increase the ease of mass production without preparing an adsorbent by grafting or impregnating an amine compound capable of adsorbing carbon dioxide and a carrier separately. As a result, it was confirmed that the amine compound and the carrier raw material were synthesized in one-pot and a spherical amine-based carbon dioxide adsorbent was synthesized through a single spray drying process, and the manufacturing process was greatly simplified, showing significant advantages in mass production. invention was completed.

An object of the present invention is not to prepare an amine compound through a method of supporting an amine compound on a carrier by grafting or impregnating an amine-based carbon dioxide adsorbent, but spray drying a solution in which an amine compound and a carrier raw material are mixed in one pot. It is to provide a method for producing a spherical amine-based carbon dioxide adsorbent, which has a significant advantage in terms of mass production by manufacturing through it.

Another object of the present invention is to provide a carbon dioxide adsorption method using the adsorbent prepared by the above method.

In order to achieve the above object, the present invention comprises the steps of: (a) adding a support material to a solution in which an amine compound is dissolved in a solvent, and then reacting; and (b) spray-drying the solution to obtain a spherical amine-based carbon dioxide adsorbent from which the solvent is removed.

The present invention also provides a carbon dioxide adsorption method using the adsorbent prepared by the above method.

The spherical amine-based carbon dioxide adsorbent according to the present invention is synthesized in one-pot and is characterized in that it undergoes a one-time spray drying process. In the case of the conventional amine-based carbon dioxide adsorbent, a process of preparing the amine compound and the support by grafting and impregnation, which are representative methods of supporting the amine compound on the support, is required, respectively. Such a general process undergoes complex processes such as grafting, impregnating, and subsequent drying of the amine material to the support, including drying and firing processes for preparing the support, which is quite disadvantageous in terms of mass production. On the other hand, the one-pot amine-based spherical amine-based carbon dioxide adsorbent according to the present invention has a significant advantage in terms of mass production because the amine compound and the carrier raw material are mixed in one-pot and manufactured by spray drying only once.

1 schematically shows a method for preparing a spherical amine-based carbon dioxide adsorbent synthesized in one-pot.
2 is a graph comparing the adsorption capacity of the spherical amine-based carbon dioxide adsorbents prepared in Preparation Example 1.
3 is an optical microscope image of the spherical amine-based carbon dioxide adsorbent “50 wt% EB-PEI/SiO ₂ ” prepared in Preparation Example 1.

The present invention can all be achieved by the following description. It should be understood that the following description describes preferred specific examples of the present invention, and the present invention is not necessarily limited thereto. In addition, the accompanying drawings are provided to aid understanding, and the present invention is not limited thereto, and details regarding individual configurations may be properly understood by the specific purpose of the related description to be described later.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is those well known and commonly used in the art.

In the present invention, instead of the method of synthesizing the amine-based carbon dioxide adsorbent in the conventional method supported by grafting and impregnating the amine compound to the carrier, a solution in which the amine compound and the carrier are mixed in one-pot is spray-dried and synthesized It was confirmed that it was easy in terms of mass production and had excellent carbon dioxide adsorption performance.

Accordingly, the present invention, at one point, (a) adding a support material to a solution in which an amine compound is dissolved in a solvent, followed by reacting; and (b) spray-drying the solution to obtain a spherical amine-based carbon dioxide adsorbent from which the solvent is removed.

In another aspect, the present invention relates to a carbon dioxide adsorption method using the adsorbent prepared by the above method.

In the present invention, the step of reacting means a step of obtaining a uniformly mixed solution by stirring the solution.

In an embodiment of the present invention, (i) adding a support material to a solution in which an amine compound is dissolved in a solvent; (ii) stirring the solution of step (i) to obtain a uniformly mixed solution; and (iii) spray-drying the (ii) solution to obtain a spherical amine-based carbon dioxide adsorbent from which the solvent is removed.

In the present invention, the amine compound may include a unit skeleton structure represented by the following Chemical Formula 1 or Chemical Formula 2.

[Formula 1]

-[(CH ₂ ) _x -NR] _y -

Here, R is hydrogen or a linear or branched alkyl group having 1 to 18 carbon atoms, x = an integer of 2 to 6, and y = an integer of 1 to 100.

[Formula 2]

-[(CH ₂ ) _x -NH ₂ ]

Here, x = an integer of 2 to 6.

In Formulas 1 and 2, it may preferably include polyalkyleneimine such as polyethyleneimine basic structure (when x=2) or polypropyleneimine basic structure (when x=3).

In the present invention, the amine compound is ethylenediamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, polyethyleneimine. (Polyethyleneimine), may include polypropyleneimine (Polypropyleneimine). In addition, the amine compound may include an ethyleneimine-type amine compound including a hydroxyl group-containing carbon chain represented by the following formula (3).

[Formula 3]

Here, X is a hydroxy group or a linear or branched alkyl group having 1 to 18 carbon atoms containing a hydroxy group, and m = an integer of 1 to 100.

In Chemical Formula 3, preferably, X is a hydroxyl group, a linear or branched alkyl group having 1 to 4 carbon atoms containing a hydroxyl group, and m is an integer of 2 to 20.

In the present invention, the support material may be selected from the group consisting of silica, alumina, activated carbon, zeolite, and metal-organic frameworks (MOF), preferably silica.

In the present invention, the solution in which the amine compound and the carrier raw material are mixed may further include an additive, and the additive may be selected from the group consisting of sodium silicate, calcium silicate, calcium aluminate and bentonite, preferably may be sodium silicate.

In the case of adding the additive, when the mixed solution is spray-dried, the additive acts as a binder that can strongly bind the support materials, thereby improving the strength of the adsorbent.

In the present invention, the additive is 0.1-20 wt%, preferably 5-10 wt%, based on the mass of the carrier compound. If the amine compound is less than 0.1% by weight, the strength may not be sufficient because the ratio of the additive to the carrier compound is low, and if it exceeds 20% by weight, the additive excessively added compared to the carrier compound serves as a binder to increase the strength. The adsorption rate may be reduced by blocking the pores of the carrier beyond that, thereby inhibiting the diffusion of carbon dioxide into the adsorbent.

In the present invention, the solvent may be selected from the group consisting of water, methanol, ethanol, acetone, acetonitrile, methyl chloride, carbon tetrachloride, hexane, cyclohexane, benzene, toluene and tetrahydrofuran, preferably water. .

In the present invention, the amine compound is 5-75 wt%, preferably 40-60 wt%, based on the total mass of the adsorbent. If the amine compound is less than 5% by weight, the ratio of carbon dioxide can be adsorbed in the adsorbent is lowered, so that the amount of carbon dioxide adsorbed relative to the weight of the adsorbent is lowered. Physical stability may be lowered due to a decrease in the ratio of the amine compound to the total adsorbent, and as the ratio of the amine compound increases, the pores of the carrier are blocked to prevent carbon dioxide from diffusing into the adsorbent, thereby reducing the adsorption rate. (Please add the critical significance according to the numerical limitation range)

In the present invention, the porous carrier may be present in an amount of 20 to 90% by weight, preferably 30 to 60% by weight, based on the total mass of the adsorbent. When the porous carrier is less than 20% by weight, there is no remaining porosity in the carrier due to the excessively supported amine, so that the diffusion of carbon dioxide is not made, so that the amine efficiency is greatly reduced, and when it exceeds 90% by weight, the specific gravity of the active material amine is Since it is significantly reduced, the carbon dioxide adsorption capacity is greatly reduced.

In the present invention, a solution in which an amine compound and a carrier raw material are mixed for preparing a spherical amine-based carbon dioxide adsorbent synthesized in one-pot can be prepared by adding an amine compound and a carrier to a solvent and stirring.

In the present invention, the amount of the amine compound: carrier raw material: solvent may be 1: 0.1-5: 1-10 (weight ratio), preferably 1: 0.5-1.5: 3-5 (weight ratio). have. If the solvent is less than 1 weight ratio, the amount of the solvent may not be enough to mix well with the amine compound and the support raw material being well dispersed. The energy required for contrast drying may be excessively consumed.

In the present invention, the spherical amine-based carbon dioxide adsorbent may have a diameter of 20 to 500 μm, preferably 50 to 300 μm. If the diameter of the adsorbent is less than 20 μm, when it is applied to the capture process after actual combustion, the gas in the process passes through the adsorbent layer and a large pressure drop occurs, resulting in a decrease in process efficiency. Since the area is small, it may be inefficient for carbon dioxide to diffuse into the adsorbent and adsorb.

In the present invention, the temperature of the spray drying apparatus for performing the spray drying method may be 333 ~ 573K, preferably 393 ~ 443K. If the temperature of the spray drying device is less than 333K, the drying temperature is low, so it takes a long time to dry all the solvents in the mixed solution, so an unnecessarily large-scale spray drying facility may be required. Adsorption performance of the produced adsorbent may be deteriorated.

Terms used herein may be defined as follows.

"Grafting" is a method of supporting a functional group included in a compound to be supported with a functional group on the surface of a support by bonding through a chemical reaction, typically an amine compound containing a silane coupling agent. refers to a method of supporting by bonding with a hydroxyl group on the surface of the silica carrier.

“Impregnation” refers to a method of impregnating a liquid material into a porous support such as alumina or silica having a large surface area and then filling the pores of the support through drying. wetness impregnation) is the most widely used method and refers to a method of manufacturing by supporting an impregnation solution corresponding to the pore volume of the carrier.

“Spray drying” refers to a method of producing a powdery material by spraying and dispersing a liquid material containing a liquid or solid content in a hot wind using a high-speed rotating disk, transporting it with a hot air, and drying it rapidly.

“One-pot synthesis” refers to the synthesis of a target compound by two or more steps, without purifying the product (intermediate product) of each step in the middle, in one reaction vessel for the next step. It refers to a synthesis in which a target compound is obtained by continuously adding reactants to react.

Hereinafter, the present invention will be described in more detail by way of Examples. These examples are merely for illustrating the present invention in more detail, and it will be apparent to those of ordinary skill in the art that the scope of the present invention is not limited to these examples.

[Preparation Example] Preparation of spherical amine-based carbon dioxide adsorbent synthesized in one-pot

The spherical amine-based carbon dioxide adsorbent synthesized in one-pot is prepared by spray-drying a solution in which an amine compound and a carrier raw material are mixed in a solvent. 1 schematically shows the manufacturing process of the adsorbent.

Preparation Example 1: Polyethylenimine (M) modified with 1,2-epoxybutane (1,2-Epoxybutane, EB) _n =1200, 19mmol N/g) as an amine compound, and one-pot preparation of an adsorbent using silica as a support

One-pot preparation of an adsorbent using the 1,2-epoxybutane-modified polyethyleneimine as an amine compound and silica as a carrier was performed.

The modified polyethyleneimine solution was stirred until completely dissolved by dissolving 30kg of polyethyleneimine in 200kg of water under 298K. After that, 18 kg of 1,2-epoxybutane to the nitrogen atom (N) present in the polyethyleneimine was added to the stirred polyethyleneimine aqueous solution so that the molar (mol) ratio of 1,2-epoxybutane was 0.37. , a modified polyethyleneimine/water solution was synthesized by further stirring for 12 hours.

Fumed silica and sodium silicate as silica carrier raw materials were added to the modified polyethyleneimine/water solution, and the ratio of the amine compound to the total adsorbent was 50 wt%, 47.5 wt%, 45 wt% Weight %, adjusted to be 40 wt%. The amounts added (fumed silica, sodium silicate) were 50 wt%, 47.5 wt%, 45 wt%, 40 wt%, respectively (41.5kg, 4.1kg), (45.5kg, 4.55kg), (50.5kg, 5.05kg ), (62 kg, 6.2 kg) were added and stirred until a uniform solution was formed.

Thereafter, the solutions prepared in the one-pot were sprayed in a spray drying apparatus to form fine droplets, and water was evaporated using a hot drying gas (air) of 423K to dry the amine compound and the carrier. The samples prepared as described above were treated as “50wt% EB-PEI/SiO ₂ ”, “47.5wt% EB-PEI/SiO ₂ ”, “45wt% EB-PEI/SiO 2 ”, “40wt% EB-PEI/SiO ₂ ”, respectively. ₂ ".

Comparative Preparation Example 1: Polyethyleneimine (M) modified with 1,2-epoxybutane (1,2-Epoxybutane, EB) _n =1200, 19 mmol N/g) as an amine compound and silica as a support for the initial wet impregnation of an adsorbent

The 1,2-epoxybutane-modified polyethyleneimine was used as an amine compound, and an initial wet impregnation method of an adsorbent having silica as a carrier was prepared.

The modified polyethyleneimine solution was stirred until completely dissolved by dissolving 30kg of polyethyleneimine in 96kg of water under 298K. After that, 18 kg of 1,2-epoxybutane to the nitrogen atom (N) present in the polyethyleneimine was added to the stirred polyethyleneimine aqueous solution so that the molar (mol) ratio of 1,2-epoxybutane was 0.37. , a modified polyethyleneimine/water solution was synthesized by further stirring for 12 hours.

To synthesize the silica carrier, 40 kg of fumed silica and 7 kg of colloidal silica (Silica sol) were added to 280 kg of water and stirred until completely uniform. Thereafter, the silica solution was sprayed in a spray drying apparatus to form fine droplets, and water was evaporated using a hot drying gas (air) of 423K to synthesize a dried silica carrier. Thereafter, the dried silica carrier was calcined at 600° C. for 6 hours to synthesize a silica carrier.

Thereafter, the silica carrier was supported in the modified polyethyleneimine/water solution by using an initial wet impregnation method to contain 50% of the total weight of the adsorbent. After removing the solvent by heat-treating the supported adsorbent in a vacuum oven at 100° C. for 12 hours, silica adsorbents on which modified polyethyleneimine was supported by an initial wet impregnation method were synthesized, and this was “50wt% impregnated EB-PEI/SiO ₂ marked with ".

Example 1: Evaluation of carbon dioxide adsorption capacity of spherical amine-based carbon dioxide adsorbent synthesized in one-pot

The carbon dioxide adsorption capacity of the spherical amine-based carbon dioxide adsorbents synthesized in one-pot prepared in Preparation Example 1 was evaluated as follows, and the results are shown in FIG. 2 .

The adsorption capacity was analyzed by thermogravimetric analysis (TGA). About 20 mg of adsorbent is placed in a TGA pan, and 100% nitrogen (N ₂ ) is flowed at 50 sccm to desorb the gases adsorbed on the surface of the adsorbent. 15% CO ₂ , 85% N ₂ was flowed at 50 sccm and maintained at 60° C. for 30 minutes.

Figure 2 is a graph showing the adsorption capacity of the amine-based carbon dioxide adsorbents synthesized in one-pot prepared in Preparation Example 1.

As a result, in the case of the spherical amine-based carbon dioxide adsorbent synthesized in one-pot, it was confirmed that the carbon dioxide adsorption capacity increased when the ratio of the amine compound to the total adsorbent increased. However, it was confirmed that when the ratio of the amine compound to the total adsorbent was 50% by weight or more, the adsorption rate of carbon dioxide was slower than that of the adsorbents having a lower ratio. It can be inferred that the ratio of the amine compound to the total adsorbent increases while blocking the pores of the carrier to suppress the diffusion of carbon dioxide into the adsorbent, thereby decreasing the adsorption rate.

Example 2 Optical microscope analysis of spherical amine-based carbon dioxide adsorbent synthesized in one-pot

3 is an optical microscope image of the spherical amine-based carbon dioxide adsorbent “50wt% EB-PEI/SiO ₂ ” prepared in Preparation Example 1.

As shown in FIG. 3, as a result of spray-drying the solution in which the amine compound and the carrier raw material are dissolved, it can be confirmed that spherical particles having a diameter of 50 to 110 μm are produced, and the amine compound and the carrier are not separated. It can be confirmed that the form is uniformly assembled.

As described above in detail a specific part of the content of the present invention, for those of ordinary skill in the art, it is clear that this specific description is only a preferred embodiment, and the scope of the present invention is not limited thereby. something to do. Accordingly, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (12)

A method for preparing a spherical amine-based carbon dioxide adsorbent comprising the steps of:
(a) adding a support material to a solution in which an amine compound is dissolved in a solvent, followed by reacting; and
(b) spray-drying the solution to obtain a spherical amine-based carbon dioxide adsorbent from which the solvent is removed.
The method according to claim 1, wherein the amine compound comprises a unit skeleton structure represented by the following Chemical Formulas 1 and 2.
[Formula 1]
-[(CH ₂ ) _x -NR] _y -
Here, R is hydrogen or a linear or branched alkyl group having 1 to 18 carbon atoms, x = an integer of 2 to 6, and y = an integer of 1 to 100.
[Formula 2]
-[(CH2) _x -NH ₂ ]
Here, x = an integer of 2 to 6.
According to claim 1, wherein the amine compound is ethylenediamine (Ethylenediamine), triethylenetetramine (Triethylenetetramine), tetraethylenepentaamine (Tetraethylenepentamine), pentaethylenehexaamine (Pentaethylenehexamine), hexaethyleneheptamine (Hexaethyleneheptamine), polyethylene Method, characterized in that at least one selected from the group consisting of imine (Polyethyleneimine), polypropyleneimine (Polypropyleneimine), and ethyleneimine-type amine compounds containing a carbon chain containing a hydroxyl group represented by the following formula (3).
[Formula 3]

Here, X is a hydroxy group or a linear or branched alkyl group having 1 to 18 carbon atoms containing a hydroxy group, and m = an integer of 1 to 100.
The method according to claim 1, wherein the support material is selected from the group consisting of silica, alumina, activated carbon and zeolite.
The method according to claim 1, wherein the solution further comprises an additive selected from the group consisting of sodium silicate, calcium silicate, calcium aluminate and bentonite.
The method according to claim 1, wherein the solvent is selected from the group consisting of water, methanol, ethanol, methyl chloride, carbon tetrachloride and tetrahydrofuran.
The method according to claim 1, wherein the amine compound is present in an amount of 5-75 wt% based on the total mass of the adsorbent.
The method according to claim 1, wherein the support is in an amount of 25-95 wt% based on the total mass of the adsorbent.
The method according to claim 1, wherein the amine compound: support material: solvent ratio is 1: 0.1-5: 1-10 (weight ratio).
The method according to claim 1, wherein the adsorbent has a diameter of 20-500 μm.
The method according to claim 1, wherein the drying is spray-dried at a temperature of 333-573K.
A method for adsorbing carbon dioxide using an adsorbent prepared by the method according to any one of claims 1 to 11.

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