TWI647001B - Method for recovering carbon dioxide - Google Patents

Abstract

A carbon dioxide recovery method comprising the steps of: adding water to a capture agent that has captured carbon dioxide to desorb carbon dioxide from the captured carbon dioxide capture agent, wherein the capture agent is selected from the group consisting of ionic liquids for capturing carbon dioxide, A solution having a total carbon number of potassium salt of a monoprotic carboxylic acid of 12 or less or a combination of the above; and collecting desorbed carbon dioxide. The carbon dioxide recovery method of the present invention can desorb carbon dioxide from the trapping agent that has captured carbon dioxide by adding water, and can effectively collect and recover carbon dioxide for subsequent reuse, and has the advantages of convenient operation and substantial time saving for desorption of carbon dioxide.

Description

Carbon dioxide recovery method

The present invention relates to a method for recovering carbon dioxide, and more particularly to a method for recovering carbon dioxide by adding water to a trapping agent that has captured carbon dioxide to desorb carbon dioxide from the trapping agent that has captured carbon dioxide.

The more active way to protect the global environment and resources is to adopt an artificial carbon cycle that recycles carbon dioxide re-synthesis chemicals. The key technology is how to capture the carbon dioxide that has been produced and further desorb carbon dioxide for subsequent reuse. For example, the method of trapping carbon dioxide by an ionic liquid has become an mainstream technology in the field of carbon dioxide recovery in recent years because of its high efficiency, cleanness, and easy desorption of carbon dioxide.

Chinese Patent Publication No. CN 102151468A discloses a method for capturing carbon dioxide by using a highly stable alkaline ionic liquid, which is a carbon dioxide gas captured by a weakly alkaline quaternary phosphorus type ionic liquid, wherein the pressure of capturing carbon dioxide is 0.0001 to 0.2. MPa, temperature is 10 to 70 ° C, and the time is 0.1 to 2 hours. In the above method, the trapped carbon dioxide is desorbed from the alkaline ionic liquid by heating, the heating temperature at which carbon dioxide is desorbed is 80 to 150 ° C, and the carbon dioxide desorption time is 0.1 to 3 hours.

Another Chinese patent publication CN 103752134A discloses a method for efficient energy-saving carbon capture of ionic liquids, which captures carbon dioxide gas by anion-functionalized ionic liquid containing a carbonyl group, and the pressure when capturing carbon dioxide is 0.0001 to 0.2 MPa, and the temperature is 20 To 100 ° C, the time is 0.1 to 3 hours. The patent publication also desorbs the trapped carbon dioxide from the carbonyl-containing anion-functionalized ionic liquid by heating, the heating temperature at which the carbon dioxide is desorbed is 60 to 120 ° C, and the carbon dioxide desorption time is 0.1 to 3 hours.

Both of the above patent publications use an ionic liquid to capture carbon dioxide and desorb the trapped carbon dioxide in a heated manner. Although carbon dioxide can be efficiently recovered for subsequent reuse, the carbon dioxide is desorbed to a high temperature (up to as high as possible). 150 ° C) and long desorption time (up to 3 hours), but still have the disadvantage of too long desorption time and energy consumption.

Accordingly, it is an object of the present invention to provide a carbon dioxide recovery process that is easy to operate and that provides significant savings in desorption time.

Thus, the carbon dioxide recovery method of the present invention comprises the steps of: adding water to a capture agent that has captured carbon dioxide to desorb carbon dioxide from the captured carbon dioxide capture agent, wherein the capture agent is selected from the group consisting of carbon dioxide capture. An ionic liquid, a solution having a total carbon number of 12 or less monopotassium carboxylic acid potassium salt or a combination thereof; and collecting desorbed carbon dioxide.

The effect of the present invention is that the carbon dioxide recovery method is capable of desorbing carbon dioxide from a trapping agent that has captured carbon dioxide by means of adding water. The carbon dioxide recovery method can effectively recover carbon dioxide for subsequent reuse, and has the advantages of simple operation and substantial saving of desorption time.

The contents of the present invention will be described in detail below:

Preferably, the carbon dioxide capture ionic liquid is selected from the group consisting of ionic liquids having a pH in the range of 6.5 to 7.5. More preferably, the ionic liquid for capturing carbon dioxide is selected from the group consisting of Imidazolium-based ionic liquids. Still more preferably, the imidazole-based ionic liquid has the structure of Chemical Formula 1, [Chemical Formula 1] In Chemical Formula 1, R ¹ and R ² each independently represent a C ₁ to C ₆ aliphatic hydrocarbon group; and R ³ to R ⁵ each independently represent hydrogen or a C ₁ to C ₆ aliphatic hydrocarbon group; ⁶ represents an aliphatic hydrocarbon group of C ₁ to C ₆ . Preferably, the C ₁ to C ₆ aliphatic hydrocarbon group in Chemical Formula 1 is an alkane group selected from C ₁ to C ₆ , an C ₂ to C ₆ alkene group, or a C ₂ to C ₆ alkyne group. More preferably, the C ₁ to C ₆ aliphatic hydrocarbon group is an alkane group selected from C ₁ to C ₆ or a C ₂ to C ₆ alkene group. Preferably, R ³ represents hydrogen. More preferably, R ³ to R ⁵ represent hydrogen.

Most preferably, the imidazole ionic liquid is selected from the group consisting of 1-butyl-3-methylimidazolium acetate, 1-allyl-3-methylimidazolium acetate (1-allyl-3-methylimidazolium acetate) 1-allyl-3-methylimidazolium acetate) or a combination of the above.

The solution of the potassium salt of the monoprotic carboxylic acid having a total carbon number of 12 or less includes the potassium salt of the monoprotic carboxylic acid having a total carbon number of 12 or less, and a solvent. The solvent is not particularly limited as long as it can dissolve the potassium salt of the monoprotic carboxylic acid having a total carbon number of 12 or less and does not affect the function of capturing the carbon dioxide of the potassium salt of the monoprotic carboxylic acid having a total carbon number of 12 or less, and the subsequent desorption of carbon dioxide. Just fine.

Preferably, the solution of the potassium salt of the monoprotic carboxylic acid having a total carbon number of 12 or less is selected from the group consisting of potassium acetate solution, potassium propionate solution or potassium butyrate solution.

The potassium acetate solution includes potassium acetate and a solvent capable of dissolving potassium acetate. The solvent is not particularly limited as long as it can dissolve the potassium acetate without affecting the function of the potassium acetate to capture carbon dioxide and the subsequent desorption of carbon dioxide. The solvent is, for example but not limited to, water, dimethyl sulfoxide (DMSO) or dimethylformamide (DMF); preferably, the solvent is water. The weight molar concentration of the potassium acetate solution is not particularly limited, and is, for example, but not limited to, 5 to 20 m.

The potassium propionate solution includes potassium propionate and a solvent capable of dissolving potassium propionate. The solvent is not particularly limited as long as it can dissolve the potassium propionate without affecting the function of the potassium propionate to capture carbon dioxide and the subsequent desorption of carbon dioxide. The solvent is, for example but not limited to, water, dimethyl hydrazine or dimethylformamide; preferably, the solvent is water. The weight molar concentration of the potassium propionate solution is not particularly limited, and is, for example, but not limited to, 5 to 20 m.

The potassium butyrate solution includes potassium butyrate and a solvent capable of dissolving potassium butyrate. The solvent is not particularly limited as long as it can dissolve the potassium butyrate without affecting the function of the potassium butyrate to capture carbon dioxide and the subsequent desorption of carbon dioxide. The solvent is, for example but not limited to, water, dimethyl hydrazine or dimethylformamide; preferably, the solvent is water. The weight molar concentration of the potassium butyrate solution is not particularly limited, and is, for example, but not limited to, 5 to 20 m.

Preferably, the temperature of the water ranges from 20 to 50 °C. The amount of the water to be used is not particularly limited and can be freely adjusted according to the amount of carbon dioxide actually captured. Preferably, the amount of water is from 30% to 50% by weight based on the total weight of the captured carbon dioxide-trapping agent.

Preferably, the water is added to the captured carbon dioxide capture agent at atmospheric pressure. Preferably, the water is added to the captured carbon dioxide capture agent at 20 to 50 °C. The carbon dioxide recovery method desorbs carbon dioxide from the captured carbon dioxide capture agent by adding water without desorbing carbon dioxide by heating.

There is no particular restriction on the manner in which desorbed carbon dioxide is collected. Preferably, the desorbed carbon dioxide is collected by a drainage gas collection method.

The present invention will be further illustrated by the following examples, but it should be understood that this embodiment is intended to be illustrative only and not to be construed as limiting.

[Example 1] Carbon dioxide recovery method

The carbon dioxide gas was passed into a reaction flask containing 10.45 g of 1-butyl-3-methylimidazolium acetate (hereinafter referred to as BMIM-OAc), and reacted under atmospheric pressure (0.1 MPa) and 29 ° C reaction conditions. After 45 minutes, a capture agent that captured carbon dioxide was obtained (total weight 11.1 grams, carbon dioxide capture amount 0.65 grams). Next, 4.5 g of water (water temperature of 30 ° C) was also added to the reaction flask under the conditions of atmospheric pressure and 29 ° C, at which time bubbles of carbon dioxide began to bubble from the carbon dioxide capture agent in the reaction flask. In the middle, the desorbed carbon dioxide is collected by the drainage gas collection method. The carbon dioxide desorption amount was 0.62 g from the bubble which started to emit carbon dioxide to the bubble which did not emit carbon dioxide for 10 seconds (that is, the desorption time of carbon dioxide).

[Examples 2 to 7] Carbon dioxide recovery method

Examples 2 to 7 were carried out in the same manner as in Example 1, except that the scavenger in Example 2 was 1-allyl-3-methylimidazolium acetate (hereinafter referred to as AMIM-OAc); in Example 3 The capture agent was an aqueous potassium propionate solution (weight mole concentration was 16 m); the capture agent in Example 4 was an aqueous potassium butyrate solution (weight mole concentration was 16 m); the capture agent in Example 5 was potassium acetate. Aqueous solution (weight molar concentration is 20 m); the capture agent in Example 6 is an aqueous potassium acetate solution (weight molar concentration is 15 m); the capture agent in Example 7 is an aqueous potassium acetate solution (weight molar concentration is 10) m). The amounts of the capturing agent, the amount of water, the desorption time, the amount of carbon dioxide captured, and the amount of desorption in Examples 1 to 7 are shown in Table 1.

[Comparative Example 1] Carbon dioxide recovery method

The carbon dioxide gas was passed into a reaction flask containing 10 g of 1-butyl-3-methylimidazolium acetate, and reacted under atmospheric pressure at 29 ° C for 45 minutes to obtain a capture agent capable of capturing carbon dioxide. (The total weight is 10.947 grams and the carbon dioxide capture is 0.947 grams). Next, the reaction flask was heated to 80 ° C under atmospheric pressure, at which time bubbles of carbon dioxide which began to appear in the reaction flask emerged from the captured carbon dioxide capture agent, while desorbed carbon dioxide was collected by a drain gas collection method. The carbon dioxide desorption amount was 0.894 g from the bubble which started to emit carbon dioxide to the bubble which no longer emitted carbon dioxide for 10 minutes (that is, the desorption time).

[Comparative Example 2] Carbon dioxide recovery method

Comparative Example 2 was carried out in the same manner as in Comparative Example 1, except that the trapping agent 1-allyl-3-methylimidazolium acetate in Comparative Example 2 was used. The amounts of the capturing agent, the heating temperature, the desorption time, the amount of carbon dioxide captured, and the desorption amount in Comparative Examples 1 and 2 are shown in Table 2.

The above various examples and comparative examples are using thermal gravity analysis-Fourier transform infrared spectroscopy (TGA-FTIR for short, wherein the FT-IR model is Varian 2000 FTIR, the receiver model is Varian TGA/IR INTERFACE, and the TGA model is TGAQ50) detects that carbon dioxide is captured in the capture agent that has captured carbon dioxide. And using thermal gravity analysis-Fourier-transformed infrared spectroscopy and clarified lime water detection, the gas desorbed from the captured carbon dioxide capture agent is indeed carbon dioxide. Among them, in the thermal gravity analysis-Fourier-transformed infrared spectrum, an absorption peak at a position of 2400 cm ^-1 can prove that the gas captured and desorbed is indeed carbon dioxide.

Table 1

Table 2

As is apparent from Tables 1 and 2, Examples 1 to 7 were able to effectively desorb carbon dioxide from the captured carbon dioxide capturing agent under normal temperature and normal pressure by adding water, and the desorption time was extremely short. However, Comparative Examples 1 and 2 require heating to desorb carbon dioxide from the captured carbon dioxide capture agent, and the desorption time is very long.

In summary, the carbon dioxide recovery method of the present invention can effectively desorb carbon dioxide from the captured carbon dioxide capture agent by adding water, and the carbon dioxide recovery method can not only effectively recover carbon dioxide for subsequent reuse, but also has the function of carbon dioxide recovery. The advantages of the present invention can be achieved by the convenience of operation and the significant saving in the desorption time.

However, the above is only the embodiment of the present invention, and the scope of the invention is not limited thereto, and all the equivalent equivalent changes and modifications according to the scope of the patent application and the patent specification of the present invention are still The scope of the invention is covered.

Claims (9)

A carbon dioxide recovery method comprising the steps of: adding water to a capture agent that has captured carbon dioxide to desorb carbon dioxide from the captured carbon dioxide capture agent, wherein the capture agent is selected from the group consisting of ionic liquids for capturing carbon dioxide. Or an aqueous solution of water and a potassium salt of a monoprotic carboxylic acid having a total carbon number of 12 or less, which is a potassium salt of a monoprotic carboxylic acid having a total carbon number of 12 or less, and the water added to the capturing agent capable of capturing carbon dioxide The amount ranges from 30% to 50% of the total weight of the captured carbon dioxide capture agent; and the desorbed carbon dioxide is collected. The carbon dioxide recovery method according to claim 1, wherein the carbon dioxide capture ionic liquid is selected from the group consisting of ionic liquids having a pH ranging from 6.5 to 7.5. The carbon dioxide recovery method according to claim 1 or 2, wherein the carbon dioxide capture ionic liquid is selected from the group consisting of imidazole-based ionic liquids. The method for recovering carbon dioxide according to claim 3, wherein the imidazole-based ionic liquid has the structure of Chemical Formula 1, In Chemical Formula 1, R ¹ and R ² each independently represent a C ₁ to C ₆ aliphatic hydrocarbon group; R ³ to R ⁵ each independently represent hydrogen or a C ₁ to C ₆ aliphatic hydrocarbon group; and R ⁶ represents C ₁ An aliphatic hydrocarbon group to C ₆ . The method for recovering carbon dioxide according to claim 4, wherein the imidazole-based ionic liquid is selected from the group consisting of 1-butyl-3-methylimidazolium acetate, 1-allyl-3-methylimidazolium acetate or the above a combination of one. The carbon dioxide recovery method according to claim 1, wherein the aqueous solution of the potassium salt of the monoprotic carboxylic acid having a total carbon number of 12 or less is selected from the group consisting of potassium acetate aqueous solution, potassium propionate aqueous solution or potassium butyrate aqueous solution. The carbon dioxide recovery method according to claim 1, wherein the temperature of the water ranges from 20 to 50 °C. The carbon dioxide recovery method according to claim 1, wherein the water is added to the captured carbon dioxide capture agent at atmospheric pressure. The carbon dioxide recovery method according to claim 1, wherein the water is added to the captured carbon dioxide-trapping agent at 20 to 50 °C.