A method for in-situ CO2 capture and conversion using artificial photosynthesis
By simulating photosynthesis to capture CO2, and using alkylamines and catalysts in a specific solvent, the problem of toxic raw materials in the synthesis of N,N'-bis(2-hydroxyalkyl)-urea in existing technologies is solved, thus realizing the green, efficient conversion and resource utilization of CO2.
Patent Information
- Application Number
- CN202410318939.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-20
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2044-03-20
AI Technical Summary
In the existing technology, the synthesis route of N,N'-bis(2-hydroxyalkyl)-urea mainly relies on S,S'-dithiocarbonate, which is toxic and expensive, thus limiting the large-scale application of carbon dioxide fixation and organic chemical reactions.
A method for capturing CO2 using artificial photosynthesis was developed. Using CO2 and alkylamine alcohols as raw materials, N,N'-di(2-hydroxyalkyl)-urea was prepared by simulating the photosynthetic process under the combined action of catalyst and solvent. Visible light-responsive photocatalytic materials such as CeO2 were used as catalysts, and CO2 was captured and converted in situ under specific solvent and reaction conditions.
This method achieves green and environmentally friendly capture and in-situ conversion of CO2. The prepared N,N'-bis(2-hydroxyalkyl)-urea does not require the use of toxic raw materials. The process is environmentally friendly and low-cost, and easy to promote industrially.
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Figure CN118206472B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of CO2 capture and in-situ catalytic conversion technology, and particularly relates to a method for capturing and converting CO2 in-situ using artificial photosynthesis. Background Technology
[0002] With rapid economic development, the massive emission of carbon dioxide has brought serious environmental and climate problems. However, carbon dioxide is also an abundant, inexpensive, non-toxic, and recyclable carbon source, making it a promising raw material for the organic chemical industry. Utilizing carbon dioxide for organic synthesis can not only reduce the concentration of carbon dioxide in the atmosphere but also fix it into valuable organic chemicals, including N,N'-dialkylurea and dimethyl carbonate. N,N'-di(2-hydroxyalkyl)urea is widely used in catalytic reactions in various organic solvent systems. The traditional synthetic route for N,N'-di(2-hydroxyethyl)urea mainly involves the heating polymerization of S,S'-dithiocarbonate and 3-aminopropanol in methanol. However, the S,S'-dithiocarbonate used in this method is toxic and expensive, limiting the scale of the reaction and its widespread application.
[0003] Therefore, how to provide a green, environmentally friendly, and low-cost method for fixing carbon dioxide is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0004] To address the aforementioned technical problems, this invention proposes a method for in-situ conversion of CO2 captured through artificial photosynthesis.
[0005] To achieve the above objectives, the present invention provides the following technical solution:
[0006] A method for capturing and converting CO2 in situ using artificial photosynthesis involves using CO2 and alkylamine as raw materials, and under the combined action of a catalyst and a solvent, completing the capture and in-situ conversion of CO2 by simulating the artificial photosynthetic process.
[0007] Preferably, it includes the following steps:
[0008] The alkylamine, solvent and catalyst are mixed to obtain a mixture. CO2 is pre-introduced to adjust the reaction pressure, and then a simulated light source is turned on. The mixture is stirred and heated to react. After the reaction is completed, it is cooled to complete the capture and in-situ conversion of CO2.
[0009] The specific principle of the above reaction is as follows:
[0010]
[0011] Preferably, the concentration of alkylamine in the mixture is 20-90 wt%, more preferably 30-70%, and the molar ratio of the catalyst to alkylamine is 0.01-4.00:100, more preferably 0.05-2.0:100.
[0012] Preferably, the catalyst is a photocatalytic material with visible light response, preferably a semiconductor material, including organic and inorganic semiconductor materials, and modified semiconductor materials thereof, more preferably CeO2 with different morphologies, and even more preferably nanocubic CeO2.
[0013] Preferably, the solvent is one or a mixture of any of the following: ethanol, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, diethylene glycol dimethyl ether, 1,3-dimethyl-2-imidazolinone, methyl tert-butyl ether, dioxane, and ionic liquid.
[0014] Preferably, the ionic liquid has a Lewis basic functional group or Basic functional group.
[0015] Preferably, the alkylamine is one or a mixture of any of the following: ethanolamine, 3-aminopropanol, 3-aminobutanol, and (2)-amino-1-butanol, with 3-aminopropanol being the most preferred.
[0016] Preferably, the simulated artificial photosynthesis process uses a simulated light source, which is a xenon lamp light source with a wavelength of 350-780nm, an operating voltage of 10-80V, preferably 12-15V, and an operating current of 0.5-2.5A, preferably 1.0-2.0A.
[0017] Preferably, the reaction temperature is 20–160°C, more preferably 50–120°C, the pressure is 0.1–5.0 MPa, more preferably 0.8–1.5 MPa, and the time is 0.1–24 h, more preferably 1–12 h.
[0018] Compared with the prior art, the present invention has the following advantages and technical effects:
[0019] This invention simulates artificial photosynthesis by using alkylamines to capture CO2 and then catalytically convert it in situ to prepare N,N'-di(2-hydroxyalkyl)-urea. This achieves two goals at once: capturing CO2 and utilizing it in situ. It eliminates the need for toxic raw materials, is environmentally friendly, uses readily available and low-cost raw materials, and is easy to promote and apply industrially. Attached Figure Description
[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:
[0021] Figure 1 The gas phase spectrum obtained in Example 1;
[0022] Figure 2 Table of GC-MS spectra analysis for N,N'-bis(2-hydroxyethyl)-urea. Detailed Implementation
[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0025] This invention discloses a method for capturing and converting CO2 in situ using artificial photosynthesis. Using CO2 and alkylamine as raw materials, CO2 is captured and converted in situ by simulating the artificial photosynthetic process under the combined action of a catalyst and a solvent.
[0026] In a preferred embodiment, the specific steps include:
[0027] The alkylamine, solvent and catalyst are mixed to obtain a mixture. CO2 is pre-introduced to adjust the reaction pressure, and then a simulated light source is turned on. The mixture is stirred and heated to react. After the reaction is completed, it is cooled to complete the capture and in-situ conversion of CO2.
[0028] The specific reaction principle is as follows:
[0029]
[0030] In a preferred embodiment, the concentration of the alkylamine in the mixture is 20-90 wt%, preferably 30-70%, and the molar ratio of the catalyst to the alkylamine is 0.01-4.00:100, preferably 0.05-2.0:100.
[0031] In a preferred embodiment, the catalyst is a photocatalytic material with visible light response, preferably a semiconductor material, including organic and inorganic semiconductor materials, and modified semiconductor materials thereof, more preferably CeO2 with different morphologies, and even more preferably nanocubic CeO2.
[0032] In a preferred embodiment, the solvent is one or a mixture of any of the following: N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, diethylene glycol dimethyl ether, 1,3-dimethyl-2-imidazolinone, methyl tert-butyl ether, dioxane, and ionic liquid.
[0033] In a preferred embodiment, the ionic liquid has a Lewis basic functional group or Basic functional group.
[0034] In a preferred embodiment, the alkylamine is one or a mixture of any of ethanolamine, 3-aminopropanol and (2)-amino-1-butanol, preferably 3-aminopropanol;
[0035] In a preferred embodiment, a simulated light source is used in the simulated artificial photosynthesis process, and the simulated light source is a xenon lamp light source with a wavelength of 350-780nm, an operating voltage of 10-80V, preferably 12-15V, and an operating current of 0.5-2.5A, preferably 1.0-2.0A.
[0036] In a preferred embodiment, the reaction temperature is 20–160°C, preferably 50–120°C, the pressure is 0.1–5.0 MPa, preferably 0.8–1.5 MPa, and the time is 0.1–24 h, preferably 1–12 h.
[0037] Unless otherwise specified, the room temperature in the embodiments of the present invention is 25±2℃.
[0038] All raw materials used in the embodiments of this invention were purchased through commercial channels.
[0039] Among them, ordinary CeO2 was purchased from Shanghai Jizhi Biochemical Technology Co., Ltd., CAS No: 1306-38-3;
[0040] Nanocubic CeO2 was prepared by a hydrothermal method;
[0041] The CO2 in the flue gas from the coal-fired power plant comes from Guangzhou Danoutong Trading Co., Ltd., and the CO2 content is 99.9%.
[0042] Example 1
[0043] A method for in-situ CO2 capture and conversion via artificial photosynthesis includes the following steps:
[0044] 12 ml (approximately 0.2 mol) of ethanolamine, 12 ml of ethanol, and 10 mmol of ordinary CeO2 were added sequentially to a high-pressure reactor and mixed thoroughly. CO2 was pre-introduced, and the CO2 pressure inside the high-pressure reactor was adjusted to 1 MPa. Then, a xenon lamp with a wavelength of 350-780 nm, a working voltage of 15 V, and a light intensity of 15 A was turned on. The magnetic stirring speed was set to 400 rpm, and the reaction temperature was gradually increased to 110 °C. The reaction was then kept at a constant temperature for 4 h under mechanical stirring. After the reaction was completed, the high-pressure reactor was cooled to room temperature, and the product was removed. The reactants and products were quantitatively analyzed by gas chromatography (GC Agilent 7890B).
[0045] Figure 1 The gas phase spectrum of the product obtained in Example 1 is shown below. Figure 1 It can be seen that the peak at 2.721 min is ethanol; at 5.613 min it is ethanolamine; at 8.611 min it is the target product N,N'-bis(2-hydroxyethyl)-urea; at 10.381 min it is 2-oxazolidinone; and at 13.004 min it is 1-(2-hydroxyethyl)-2-imidazolinone.
[0046] Figure 2 The table below shows the GC-MS spectrum analysis of N,N'-bis(2-hydroxyethyl)-urea. By analyzing the missing fragments and elemental composition, it can be confirmed that the peak at 8.611 min in the gas phase spectrum is N,N'-bis(2-hydroxyethyl)-urea.
[0047] The calculation methods for CO2 capture-in-situ catalytic conversion, selectivity, and yield are as follows:
[0048] The formula for calculating amine conversion rate is: α=(1-A sp / A st )×100%, A sp and A st The peak areas of the sample and the standard are respectively; the selectivity of each component in the reaction product is calculated by the area normalization method, and the yield can be obtained by the conversion rate of amine and the selectivity of N,N'-bis(2-hydroxyethyl)-urea.
[0049] The final measured CO2 capture-in-situ catalytic conversion rate was 17.24%.
[0050] The product composition, selectivity, and yield are shown in Table 1:
[0051] Table 1
[0052] Product components Selectivity (%) Yield (%) N,N'-Di(2-hydroxyethyl)-urea 35.19 6.27 2-Oxazolidinone 31.43 5.60 1-(2-hydroxyethyl)-2-imidazolinone 33.38 5.75
[0053] Example 2
[0054] A method for in-situ CO2 capture and conversion via artificial photosynthesis includes the following steps:
[0055] 12 ml (approximately 0.2 mol) of ethanolamine, 12 ml of ethanol, and 10 mmol of nano-cubic CeO2 were added sequentially to a high-pressure reactor. CO2 was pre-introduced, and the CO2 pressure inside the reactor was adjusted to 1 MPa. Then, a xenon lamp with a wavelength of 350-780 nm, an irradiance of 15 A, and a working voltage of 15 V was turned on. The magnetic stirring speed was set to 400 rpm, and the reaction temperature was gradually increased to 110 °C. The reaction was then carried out under constant temperature for 4 hours with mechanical stirring. After the reaction was completed, the high-pressure reactor was cooled to room temperature, and the product was removed. The reactants and products were quantitatively analyzed by gas chromatography (GC Agilent 7890B) using the same method as in Example 1. The CO2 capture-in-situ catalytic conversion rate was found to be 24.3%. The product composition, selectivity, and yield are shown in Table 2.
[0056] Table 2
[0057] Product components Selectivity (%) Yield (%) N,N'-Di(2-hydroxyethyl)-urea 99.1 24.08 2-Oxazolidinone 0.9 0.22 1-(2-hydroxyethyl)-2-imidazolinone 0 0
[0058] Example 3
[0059] A method for in-situ CO2 capture and conversion via artificial photosynthesis includes the following steps:
[0060] 12 ml of 3-aminopropanol, 12 ml of ethanol, and 10 mmol of ordinary CeO2 were added sequentially to a high-pressure reactor. CO2 was pre-introduced, and the CO2 pressure inside the reactor was adjusted to 1 MPa. Then, a xenon lamp source with a wavelength of 350-780 nm, an irradiance of 15 A, and a working voltage of 15 V was turned on. The magnetic stirring speed was set to 400 rpm, and the reaction temperature was gradually increased to 110 °C and then kept at a constant temperature for 4 h under mechanical stirring. After the reaction was completed, the high-pressure reactor was cooled to room temperature, and the product was taken out. The reactants and products were quantitatively analyzed by gas chromatography (GAC Gilent 7890B) using the same method as in Example 1. The CO2 capture-in-situ catalytic conversion rate was found to be 36.17%. The product composition, selectivity, and yield are shown in Table 3.
[0061] Table 3
[0062] Product components Selectivity (%) Yield (%) N,N'-Di(2-hydroxypropyl)-urea 89.12 32.23 3-oxazolidinone 10.88 3.94
[0063] Example 4
[0064] A method for in-situ conversion of CO2 captured by artificial photosynthesis, utilizing carbon dioxide from flue gas of coal-fired power plants for direct resource recovery, includes the following steps:
[0065] 12 ml of 3-amino-butanol, 12 ml of ethanol, and 10 mmol of ordinary CeO2 were added sequentially to a high-pressure reactor. CO2 was pre-introduced, and the CO2 pressure inside the reactor was adjusted to 1 MPa. Then, a xenon lamp with a wavelength of 350-780 nm, an irradiance of 15 A, and a working voltage of 15 V was turned on. The magnetic stirring speed was set to 400 rpm, and the reaction temperature was gradually increased to 110 °C. The reaction was then carried out under constant temperature for 4 h with mechanical stirring. After the reaction was completed, the high-pressure reactor was cooled to room temperature, and the product was removed. The reactants and products were quantitatively analyzed by gas chromatography (GC-Agilent 7890B) using the same method as in Example 1. The CO2 capture-in-situ catalytic conversion rate was found to be 31.21%. The product composition, selectivity, and yield are shown in Table 4.
[0066] Table 4
[0067] Product components Selectivity (%) Yield (%) N,N'-Di(2-hydroxypropyl)-urea 55.01 17.17 4-Methyloxazolidin-2-one 44..99 14.04
[0068] Example 5
[0069] A method for in-situ CO2 capture and conversion via artificial photosynthesis includes the following steps:
[0070] 12 ml of ethanolamine, 12 ml of solvent ethanol, and 10 mmol of ordinary CeO were added sequentially to a high-pressure reactor. CO2 was pre-introduced, and the CO2 pressure inside the reactor was adjusted to 2 MPa. Then, a xenon lamp source with a wavelength of 350-780 nm, an irradiance of 15 A, and a working voltage of 15 V was turned on. The magnetic stirring speed was set to 400 rpm, and the reaction temperature was gradually increased to 110 °C and then kept at a constant temperature for 4 h under mechanical stirring. After the reaction was completed, the high-pressure reactor was cooled to room temperature, and the product was removed. The reactants and products were quantitatively analyzed by gas chromatography (GC-Agilent 7890B). The CO2 capture-in-situ catalytic conversion rate was found to be 18.5%. The product composition, selectivity, and yield are shown in Table 5.
[0071] Table 5
[0072] Product components Selectivity (%) Yield (%) N,N'-Di(2-hydroxyethyl)-urea 34.17 6.32 2-Oxazolidinone 33.47 6.19 1-(2-hydroxyethyl)-2-imidazolinone 32.36 5.99
[0073] Example 6
[0074] A method for in-situ CO2 capture and conversion via artificial photosynthesis includes the following steps:
[0075] 12 ml of ethanolamine, 12 ml of 1,3-dimethyl-2-imidazolinone, and 10 mmol of ordinary CeO were added sequentially to a high-pressure reactor. CO2 was pre-introduced, and the CO2 pressure inside the reactor was adjusted to 1 MPa. Then, a xenon lamp source with a wavelength of 350-780 nm, an irradiance of 15 A, and a working voltage of 15 V was turned on. The magnetic stirring speed was set to 400 rpm, and the reaction temperature was gradually increased to 110 °C and then kept at a constant temperature for 4 h under mechanical stirring. After the reaction was completed, the high-pressure reactor was cooled to room temperature, and the product was removed. The reactants and products were quantitatively analyzed by gas chromatography (GC Agilent 7890B). The CO2 capture-in-situ catalytic conversion rate was found to be 61.42%. The product composition, selectivity, and yield are shown in Table 6.
[0076] Table 6
[0077] Product components Selectivity (%) Yield (%) N,N'-Di(2-hydroxyethyl)-urea 33.4 20.51 2-Oxazolidinone 66.6 40.91 1-(2-hydroxyethyl)-2-imidazolinone 0 0
[0078] Comparative Example 1
[0079] A method for capturing and converting CO2 in situ using artificial photosynthesis differs from Example 1 only in that CO2 from flue gas from a coal-fired power plant is used as the CO2 source, and no catalyst, ordinary CeO2, is added. All other process steps and parameters are the same as in Example 1.
[0080] The final test results showed that the CO2 capture rate of the flue gas from the coal-fired power plant was 9.24%, and the capture-in-situ catalytic conversion rate was 3.21%.
[0081] Comparative Example 2
[0082] A method for in-situ CO2 capture and conversion via artificial photosynthesis differs from Example 1 only in that it does not use a xenon lamp source for simulated illumination; all other process steps and parameters are the same as in Example 1. Specifically, it includes the following steps:
[0083] 12 ml (approximately 0.2 mol) of ethanolamine, 12 ml of ethanol, and 1 mmol of ordinary CeO2 were added sequentially to a high-pressure reactor and mixed thoroughly. CO2 was pre-introduced, and the CO2 pressure inside the high-pressure reactor was adjusted to 1 MPa. The magnetic stirring speed was set to 400 rpm, and the reaction temperature was gradually increased to 110 °C. The reaction was then kept at a constant temperature for 4 h under mechanical stirring. After the reaction was completed, the high-pressure reactor was cooled to room temperature, and the product was removed. The reactants and products were quantitatively analyzed by gas chromatography (GC Agilent 7890B).
[0084] The final test results showed that the CO2 capture rate of the flue gas from the coal-fired power plant was 3.13%, and the capture-in-situ catalytic conversion rate was 2.17%.
[0085] Comparative Example 3
[0086] A method for capturing and converting CO2 in situ using artificial photosynthesis differs from Example 1 only in that the wavelength of the xenon lamp light source is 350-780nm and the light intensity is 10A. All other process steps and parameters are the same as in Example 1.
[0087] The final detection results showed that the CO2 capture rate of the flue gas from the coal-fired power plant was 17.21%, and the capture-in-situ catalytic conversion rate was 12.31%.
[0088] Comparative Example 4
[0089] A method for capturing and converting CO2 in situ using artificial photosynthesis differs from Example 1 only in that the reaction temperature is gradually increased to 130°C and then kept at a constant temperature for 4 hours under mechanical stirring. All other process steps and parameters are the same as in Example 1.
[0090] The final detection results showed that the CO2 capture rate of the flue gas from the coal-fired power plant was 20.17%, and the capture-in-situ catalytic conversion rate was 18.11%.
[0091] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A method for in-situ synthesis of N,N'-di(2-hydroxyalkyl)-urea by capturing CO2 through artificial photosynthesis, characterized in that, Using CO2 and alkylamines as raw materials, CO2 capture and in-situ conversion are achieved through a reaction that simulates artificial photosynthesis, under the combined action of catalysts and solvents. The catalyst is cerium oxide; The alkylamine is one or a mixture of any of the following: ethanolamine, 3-aminopropanol, 3-amino-butanol and (2)-amino-1-butanol; The simulated artificial photosynthesis process uses a simulated light source, which is a xenon lamp with a wavelength of 350~780nm, an operating voltage of 10~80V, and an operating current of 0.5~2.5A.
2. The method for in-situ conversion of CO2 captured by artificial photosynthesis to synthesize N,N'-di(2-hydroxyalkyl)-urea according to claim 1, characterized in that, The solvent is one or a mixture of any of the following: ethanol, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, diethylene glycol dimethyl ether, 1,3-dimethyl-2-imidazolinone, methyl tert-butyl ether, dioxane, and ionic liquids.
3. The method for in-situ synthesis of N,N'-di(2-hydroxyalkyl)-urea by capturing CO2 through artificial photosynthesis according to claim 2, characterized in that, The ionic liquid has Lewis basic functional groups or Brønsted basic functional groups.
4. The method for in-situ synthesis of N,N'-di(2-hydroxyalkyl)-urea by capturing CO2 through artificial photosynthesis according to claim 1, characterized in that, The reaction is carried out at a temperature of 20~160℃, a pressure of 0.1~5.0MPa, and a time of 0.1~24h.