Catalytic reaction methods and systems for carbon sequestration using carbon dioxide can be recycled.

Abstract

This invention provides a recyclable catalytic reaction method for carbon fixation of carbon dioxide, comprising the following steps: Step A: dissolving a catalyst in an ionic liquid (IL) to obtain a catalyst solution; wherein the catalyst comprises silver iodide and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU); Step B: adding propargyl alcohol to the catalyst solution and then introducing carbon dioxide to catalyze the reaction between the propargyl alcohol and the carbon dioxide, thereby obtaining a cyclic carbonate; and Step C: mixing the cyclic carbonate generated in Step B with the catalyst solution, then extracting and separating the cyclic carbonate from the catalyst solution, and allowing the separated catalyst solution to be reused for the catalytic reaction as in Step B. Accordingly, this invention achieves carbon dioxide fixation and produces commercially valuable cyclic carbonates through a reusable catalyst solution.

Description

[Technical Field]

[0001] This invention relates to carbon fixation technology, and more particularly to a catalytic reaction method and system for carbon fixation of carbon dioxide that can be recycled. [Previous Technology]

[0002] As the greenhouse effect becomes increasingly severe, carbon emissions have become a global focus. To address this issue, many carbon sequestration technologies and methods have emerged, such as:

[0003] 1. Utilizing plant photosynthesis to absorb carbon dioxide: Plants convert atmospheric carbon dioxide into organic matter through photosynthesis. However, the efficiency of plant photosynthesis is relatively low, and large areas of land are needed to plant trees to achieve a significant carbon sequestration effect. In addition, trees have a long growth cycle, which may not be timely enough to meet the needs of reducing carbon emissions in the short term.

[0004] 2. Carbon Capture, Utilization and Storage (CCUS): This involves capturing carbon dioxide emitted from factories or the atmosphere and storing or reusing it underground. While these methods can effectively reduce atmospheric carbon dioxide, current technologies often require large amounts of energy, which contradicts the goal of reducing carbon emissions.

[0005] In order to improve the shortcomings of the aforementioned methods, a more efficient and energy-saving carbon fixation technology, such as a chemical reaction with good yield, would be something that relevant practitioners need to consider. [Summary of the Invention]

[0006] The main objective of this invention is to provide a catalytic reaction method for carbon fixation of carbon dioxide that can be recycled. This method uses a reusable catalyst solution to solidify carbon dioxide and produce commercially valuable cyclic carbonates.

[0007] Therefore, in order to achieve the aforementioned objective, the catalytic reaction method for carbon fixation of carbon dioxide provided by the present invention includes the following steps: Step A: Dissolving a catalyst in an ionic liquid (IL) to obtain a catalyst solution; wherein the catalyst includes silver iodide and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU); Step B: Adding a propargyl alcohol to the catalyst solution and then introducing carbon dioxide to allow the propargyl alcohol to react with the carbon dioxide in a catalytic reaction to obtain a cyclic carbonate; and Step C: The cyclic carbonate generated in Step B is mixed with the catalyst solution, and then the cyclic carbonate is extracted and separated from the catalyst solution, and the separated catalyst solution can be reused for the catalytic reaction in Step B.

[0008] In one embodiment, in step C, the cyclic carbonate is extracted with diethyl ether, and the diethyl ether mixed with the catalyst solution is removed by vacuum concentration.

[0009] In one embodiment, the molar percentage of the 1,8-diazabicyclo[5.4.0]undec-7-ene is between 1.1 mol% and 6.7 mol%.

[0010] In one embodiment, the pressure of the carbon dioxide is between 1 atm and 5 atm.

[0011] In one embodiment, the mole percentage of the silver iodide is between 0.8 mol% and 5 mol%.

[0012] In one embodiment, the amount of propargyl alcohol added is between 1.03 mmol and 6.18 mmol.

[0013] In one embodiment, the cyclic carbonate is a compound represented by the following chemical formula:

[0014] .

[0015] In one embodiment, the ionic liquid comprises any of the following organic salt compounds:

[0016] 、、、.

[0017] In one embodiment, in step B, the temperature of the catalytic reaction is between 20°C and 40°C.

[0018] In addition, the present invention also provides a catalytic reaction system for carbon sequestration of carbon dioxide, comprising a reactor for performing the aforementioned catalytic reaction method for carbon sequestration of carbon dioxide.

Implementation Method

[0020] The present invention will be further described with reference to the following embodiments, but it should be understood that the embodiments are only for illustrative purposes and should not be construed as limiting the implementation of the present invention.

[0021] First, the catalytic reaction method for carbon sequestration of carbon dioxide according to the first embodiment of the present invention includes the following steps:

[0022] Step A: Dissolve a catalyst in an ionic liquid (IL) to obtain a catalyst solution. The catalyst comprises silver iodide and 1,8-diazabicyclo[5.4.0]undec-7-ene (hereinafter referred to as DBU), wherein the molar percentage of the silver iodide is between 0.8 mol% and 5 mol%, and the molar percentage of the DBU is between 1.1 mol% and 6.7 mol%. The ionic liquid comprises any of the following organic salt compounds:

[0023] 、、、.

[0024] Step B: Propargyl alcohol is added to the catalyst solution, and carbon dioxide is then introduced to catalyze the reaction between the propargyl alcohol and the carbon dioxide, thereby obtaining a cyclic carbonate. The amount of propargyl alcohol added is between 1.03 mmol and 6.18 mmol. The pressure of the carbon dioxide is between 1 atm and 5 atm. The catalytic reaction is carried out at room temperature between 20°C and 40°C. The cyclic carbonate is a compound represented by the following chemical formula:

[0025] .

[0026] Step C: The cyclic carbonate generated in step B is mixed with the catalyst solution, and then the cyclic carbonate is extracted and separated from the catalyst solution, so that the separated catalyst solution can be reused for the catalytic reaction as in step B. Further, in step C, the cyclic carbonate is extracted with diethyl ether, and then the diethyl ether mixed with the catalyst solution is removed by vacuum concentration.

[0027] In relevant literature, such as the works published by J.-Y. Li et al. (J.-Y. Li, L.-H. Han, Q.-C. Xu, Q.-W. Song, P. Liu, K. Zhang, "Efficient Synthesis of Cyclic Carbonates from Epoxides and Carbon Dioxide," ACS Sustainable Chemistry & Engineering, 7 (2019) 3378-3388.) and Z. Zhang et al. (Z. Zhang, H. Gao, H. Wu, Y. Qian, L. Chen, J. Chen, "High-Temperature Synthesis of Cyclic Carbonates from Epoxides and Carbon Dioxide," ACS Applied Nano Materials, 1 (2018) 6463-6476.), although they achieved the synthesis of cyclic carbonates from epoxides and carbon dioxide under different conditions, all required excessively high reaction temperatures (i.e., 80°C) to carry out the synthesis reaction. Furthermore, while other related literature describes synthesis reactions that can be carried out at room temperature, they require relatively high carbon dioxide pressure. In contrast, this invention enables carbon fixation at room temperature and in an environment that avoids introducing excessively high-pressure carbon dioxide, thus possessing particular commercial value.

[0028] Furthermore, the present invention also provides a catalytic reaction system for carbon dioxide fixation that can be recycled, comprising a reactor for performing the aforementioned catalytic reaction method for carbon dioxide fixation. Specifically, the reactor is a 30 mL or 50 mL stainless steel autoclave, and the system also includes test tubes, a stirring rod, a nuclear magnetic resonance (NMR) device, a vacuum extraction and concentration device, or other common experimental instruments or equipment. Moreover, the reactor can be connected to a controller to adjust the reaction conditions during the catalytic reaction process, i.e., pressure, reaction time, reaction temperature, etc.

[0029] Specific experimental data are described below to further demonstrate the effectiveness of the present invention.

[0030] Example 1

[0031] Take a test tube and dissolve 5 mol% silver iodide in 1 mL of ionic liquid to obtain a catalyst solution, then add 1.03 mmol propargyl alcohol. Place the test tube in an autoclave, seal it, and introduce 5 atm of carbon dioxide. Stir with a stir bar at room temperature for 5 hours to overnight to carry out the catalytic reaction, thereby obtaining a cyclic carbonate. The chemical reaction formula is as follows:

[0032] Next, the cyclic carbonate was extracted multiple times with 30 mL of diethyl ether to separate it from the catalyst solution. The yield was determined by 1H NMR spectroscopy using p-xylene as an internal standard. Finally, the separated catalyst solution was evacuated under vacuum for 10 minutes to remove the diethyl ether. After adding propargyl alcohol and carbon dioxide again, the next catalytic reaction could be carried out.

[0033] In addition, the above operation was performed with different ionic liquids in Example 1, and the different ionic liquids are shown in Table 1.

[0034] Table 1. List of organic salt compounds in different ionic liquids IL 1 IL 2 IL 3 IL 4 IL 5 IL 6 IL 7 IL 8 IL 9 IL 10 IL 11 IL 12

[0035] Example 2

[0036] The difference from Example 1 is that 6.7 mol% of DBU was added to the ionic liquid. The experimental results of Example 1 and Example 2 are shown in Table 2, where N / A refers to unreacted.

[0037] Table 2. Experimental Results Serial Number Types of ionic liquids Yield (%) Example 1 (excluding DBU) Example 2 (Including DBU) 1 IL1 9 57 2 IL3 0 N / A 3 IL4 0 N / A 4 IL5 0 N / A 5 IL6 0 N / A 6 IL7 0 N / A 7 IL8 3 77 8 IL9 1 N / A 9 IL10 1 N / A 10 IL11 0 N / A 11 IL12 0 N / A

[0038] As shown in Table 2, in Example 1 without the addition of DBU, only a small number of ionic liquids reacted, and the yield was too low. In Example 2 with the addition of DBU, the yields of the two ionic liquids, IL1 and IL8, were 57% and 77%, respectively.

[0039] Furthermore, the chemical reaction formula for Example 2 is as follows:

[0040]

[0041] Example 3

[0042] Continuing with Example 2, for the experimental groups using IL 1 and IL 8 ionic liquids respectively, the catalyst solutions after extraction and vacuum treatment were then subjected to catalytic reactions. The experimental results are shown in Table 3. In the IL 1 experimental group, the catalyst solution completely solidified after the third recycling, resulting in very low yield. However, the IL 8 experimental group did not encounter the same problem with its catalyst solution.

[0043] Table 3. List of recycling tests for IL 1 and IL 8. Number of times of recycling Yield (%) Remark IL-1 experimental group IL 8 experimental group 1 57 77 2.06 mmol catalyst solution (substrate) Stop replenishing DBU 2 76 69 3 9 59 4 N / A 106 5 N / A 79 6 N / A 97 7 N / A 93 3.09 mmol catalyst solution (substrate)

[0044] Example 4

[0045] To address the solidification issue in the IL 1 experimental group in Example 3, an experimental group using IL 2 ionic liquid was used. After 10 recycling cycles, no solidification was observed, and the average yield of cyclic carbonates was 75%. Furthermore, the IL 8 experimental group still exhibited the highest conversion rate, with an average yield of 90%. This indicates that silver iodide and DBU, as catalysts, do not lose their activity after washing and extraction.

[0046] Table 4. Ionic liquids underwent 10 recycling tests. Serial Number Types of ionic liquids Average yield (%) after 10 cycles 1 IL2 75 7 IL8 90

[0047] Furthermore, the chemical reaction formula for Example 4 is as follows:

[0048]

[0049] Example 5

[0050] The difference from Example 2 is that 0.8 mol% silver iodide and 1.1 mol% DBU are dissolved in 1 mL of ionic liquid, propargyl alcohol is added at 6.18 mmol, and carbon dioxide at 1 atm is introduced. After 3 runs, the conversion rate is 64%. The chemical reaction formula is as follows:

[0051]

[0052] To this end, Example 5 illustrates the possibility of realizing the catalytic reaction of the present invention under atmospheric pressure.

[0053] Finally, based on the above examples, it can be seen that the present invention achieves the curing of carbon dioxide and the production of organic cyclic carbonates through a reusable catalyst solution. Furthermore, another feasible chemical reaction formula is listed below:

[0054]

[0055] In summary, the present invention achieves the curing of carbon dioxide and the production of commercially valuable cyclic carbonates through a reusable catalyst solution. Furthermore, the experimental data and related information above confirm that the molar percentage of the 1,8-diazabicyclo[5.4.0]undec-7-ene is between 1.1 mol% and 6.7 mol%, the pressure of the carbon dioxide is between 1 atm and 5 atm, the molar percentage of the silver iodide is between 0.8 mol% and 5 mol%, and the amount of propargyl alcohol added is between 1.03 mmol and 6.18 mmol, and these values ​​can still be changed according to actual needs; the embodiments of the present invention are not limited thereto.

[0056] The above description is merely illustrative and not restrictive. Any equivalent modifications or alterations made without departing from the spirit and scope of this invention should be included in the appended claims. [Simplified Explanation of the Diagram]

[0019] None

Claims

1. A catalytic reaction method for carbon fixation of carbon dioxide that can be recycled, comprising the following steps: Step A: dissolving a catalyst in an ionic liquid (IL) to obtain a catalyst solution; wherein, The catalyst comprises silver iodide and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU); wherein the ionic liquid comprises any one of the following organic salt compounds: , , ; Step B: Propargyl alcohol is added to the catalyst solution, and carbon dioxide is then introduced to catalyze the reaction between the propargyl alcohol and the carbon dioxide to obtain a cyclic carbonate, wherein the temperature of the catalytic reaction is between 20°C and 40°C, and the carbon dioxide pressure is between 1 atm and 5 atm; and Step C: The cyclic carbonate generated in Step B is mixed with the catalyst solution, and the cyclic carbonate is extracted and separated from the catalyst solution, and the separated catalyst solution can be re-catalyzed as in Step B.

2. The catalytic reaction method for carbon sequestration of carbon dioxide as described in claim 1, wherein, In step C, the cyclic carbonate is extracted with diethyl ether, and then the diethyl ether mixed with the catalyst solution is removed by vacuum concentration.

3. The catalytic reaction method for carbon sequestration of carbon dioxide as described in claim 1, wherein, The molar percentage of this 1,8-diazabicyclo[5.4.0]undec-7-ene ranges from 1.1 mol% to 6.7 mol%.

4. The catalytic reaction method for carbon sequestration of carbon dioxide as described in claim 1, wherein, The molar percentage of this silver iodide is between 0.8 mol% and 5 mol%.

5. A catalytic reaction method for carbon sequestration of carbon dioxide as described in claim 1, wherein, The amount of propargyl alcohol added ranged from 1.03 mmol to 6.18 mmol.

6. The catalytic reaction method for carbon sequestration of carbon dioxide as described in claim 1, wherein, The cyclic carbonate is a compound represented by the following chemical formula: .

7. A catalytic reaction system for recyclable carbon dioxide fixation, comprising a reactor for performing a catalytic reaction method for recyclable carbon dioxide fixation as described in any one of claims 1 to 6.