A silane-based amino-modified nano-silica carbon dioxide hydrate promoter, its preparation method and application

Abstract

This invention discloses a silane-based amino-modified nano-silica carbon dioxide hydrate promoter, its preparation method, and its application. The preparation method includes the following steps: (1) mixing nano-silica with aminopropyltriethoxysilane and stirring to form a homogeneous mixture; (2) heating the homogeneous mixture in an inert atmosphere to obtain modified nano-silica; (3) adding aminosilane to the modified nano-silica, continuing the reaction, and processing after the reaction to obtain modified nano-silica, which is the silane-based amino-modified nano-silica carbon dioxide hydrate promoter. This invention uses a two-step modification process with aminopropyltriethoxysilane and aminosilane to modify nano-silica, introducing amino groups to enhance its affinity for carbon dioxide. A solvent-free modification method is used, and by optimizing the reaction conditions, the modification efficiency and the final performance of the nanomaterial are improved.

Description

Technical Field

[0001] This invention belongs to the field of hydrate promoters and their preparation technology, and relates to a silane-based amino-modified nano-silica carbon dioxide hydrate promoter, its preparation method and application. Background Technology

[0002] In the capture and storage of carbon dioxide, the formation of carbon dioxide hydrates is an effective method. However, traditional promoters generally suffer from insufficient performance, high synthesis costs, and significant environmental impact. In recent years, research on modified nanomaterials has gradually increased, and modified nano-silica has attracted widespread attention due to its excellent physicochemical properties. Existing technologies rarely focus on silane-based amino-modified nano-silica as a carbon dioxide hydrate promoter. Therefore, developing novel, high-performance promoters is of significant practical importance.

[0003] However, the formation of carbon dioxide hydrates still faces several technical challenges, including harsh reaction conditions, slow formation rates, and poor stability. These problems limit the practical application and widespread adoption of this technology. The selection and application of promoters are crucial in the formation of carbon dioxide hydrates, as they can effectively improve the formation rate and stability of the hydrates.

[0004] Currently, the research and development of accelerators is gradually shifting towards materials with high catalytic performance and environmental friendliness. Researchers have begun to explore various modified materials, such as polymers and nanomaterials, to improve the carbon dioxide capture efficiency and hydrate stability. At the same time, carbon dioxide capture technology under low-temperature atmospheric conditions is also receiving increasing attention in order to reduce energy consumption and improve economic efficiency. Technical challenges that need to be addressed: (1) Slow reaction rate: Existing accelerators have a slow hydrate formation reaction rate at low temperatures, making it difficult to meet the requirements of industrial applications. (2) Poor accelerator stability: Many accelerators are prone to failure under high pressure conditions, leading to a decrease in carbon dioxide capture efficiency. (3) Insufficient environmental adaptability: The performance of some accelerators is unstable under different environmental conditions, which limits their practical application range. Summary of the Invention

[0005] To address the aforementioned technical challenges, the present invention aims to provide a silane-based amino-modified nano-silica carbon dioxide hydrate promoter, its preparation method, and its application.

[0006] This invention employs a two-step modification process using aminopropyltriethoxysilane (APTES) and aminosilane (N-(triethoxysilyl)aminopropionic acid) to modify nano-silica, introducing amino groups to enhance its affinity for carbon dioxide. A solvent-free modification method is used, and reaction conditions are optimized to improve modification efficiency and the performance of the final nanomaterial. This invention effectively promotes the hydrate formation process through the modification of nano-silica. The promoter prepared in this invention significantly improves the formation rate and stability of carbon dioxide hydrates under low temperature and high pressure conditions, exhibiting excellent catalytic performance. Simultaneously, this promoter possesses good environmental adaptability and high economic efficiency, meeting practical application requirements and providing a powerful technical solution for the efficient capture and storage of carbon dioxide.

[0007] The present invention provides a method for preparing a silane-based amino-modified nano-silica carbon dioxide hydrate promoter, comprising the following steps:

[0008] (1) Mix nano-silica with aminopropyltriethoxysilane and stir to form a homogeneous mixture; (2) The homogeneous mixture is heated and reacted in an inert atmosphere to obtain modified nano-silica; (3) Add aminosilane to the modified nano silica, continue the reaction, and process after the reaction to obtain modified nano silica, which is a silane-based amino-modified nano silica carbon dioxide hydrate promoter.

[0009] In the above preparation method, in step (1), the mass ratio of the nano-silica to the aminopropyltriethoxysilane can be 100:3~10, specifically 100:5.

[0010] In the above preparation method, in step (2), the inert atmosphere includes nitrogen; The temperature is then raised to 50℃~55℃; The reaction temperature can be 50℃~55℃, and the time can be 1~4 h, specifically 2 h, 1~2 h, or 2~4 h.

[0011] In the above preparation method, in step (3), the aminosilane is selected from at least one of aminopropyltrimethoxysilane, aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane and aminopropylphenyldimethoxysilane.

[0012] In the above preparation method, in step (3), the reaction temperature can be 60℃~65℃ and the time can be 1~6h, specifically 4h, 1~4h, or 4~6h; The mass ratio of the aminosilane to the modified nano-silica can be 1 to 5:10, specifically 3:105, 1 to 3:10, 2 to 5:10 or 2 to 7:10.

[0013] In the above preparation method, step (3) also includes the steps of centrifuging and washing the reaction system to remove unreacted aminosilane; The centrifugation speed can be 8000~12000 r / min, and the time can be 10~20 minutes to ensure complete separation.

[0014] The present invention provides the silane-based amino-modified nano-silica carbon dioxide hydrate promoter obtained by the above preparation method.

[0015] The silane-based amino-modified nano-silica carbon dioxide hydrate promoter described in this invention is applied to carbon dioxide capture and hydrate formation.

[0016] The present invention has the following beneficial effects: 1. This invention employs a two-step method involving aminopropyltriethoxysilane (APTES) and aminosilane to aminate and modify nano-silica, forming nanomaterials with amino functional groups, which provides them with strong hydrophilicity and dispersibility. During the modification process, the surface of the nano-silica forms a novel chemical structure through the introduction of aminosilane. This structure enhances the affinity for polar solvents (such as water molecules) and facilitates the formation of hydrogen bonds.

[0017] 2. The modified nano-silica surface possesses abundant amino functional groups. These amino groups can effectively adsorb carbon dioxide molecules, thereby promoting their interaction with water molecules and accelerating the formation of carbon dioxide hydrates. Through amination modification, nano-silica can provide a supporting framework, stabilize the formed hydrate structure, improve its thermodynamic stability and kinetic reaction rate, promote hydrate stability, and enhance the stability and durability of the hydrate.

[0018] 3. The reaction process adopts solvent-free reaction conditions. The reaction is carried out under solvent-free conditions, which effectively avoids the interference of moisture on the reaction and improves the efficiency of the modification reaction and the purity of the product.

[0019] 4. The silane-based amino-modified nano-silica carbon dioxide hydrate promoter of the present invention can effectively capture carbon dioxide and promote the formation of hydrates at low temperatures. Attached Figure Description

[0020] Figure 1 The induction time curve of a silane-based amino-modified nano-silica carbon dioxide hydrate promoter prepared in Example 1 of this invention.

[0021] Figure 2 The induction time curve of a silane-based amino-modified nano-silica carbon dioxide hydrate promoter prepared in Example 2 of this invention.

[0022] Figure 3 The induction time curve of the silane-based amino-modified nano-silica carbon dioxide hydrate promoter prepared in Example 3 of this invention.

[0023] Figure 4 The induction time curve of the silane-based amino-modified nano-silica carbon dioxide hydrate promoter prepared in Example 4 of this invention.

[0024] Figure 5 The induction time curves for oxide hydrates in a pure water system are shown.

[0025] Figure 6 The induction time curve is for the modified silica prepared in Comparative Example 1.

[0026] Figure 7 The induction time curve is for the silica prepared in Comparative Example 2.

[0027] Figure 8 The induction time curve is for the silica prepared in Comparative Example 3. Detailed Implementation

[0028] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0029] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0030] Example 1: 1. Material preparation: Mix 100g of nano silica with 5g of aminopropyltriethoxysilane (APTES) thoroughly and stir until homogeneous to form a homogeneous mixture.

[0031] 2. Modification reaction: Under nitrogen protection, the homogeneous mixture is heated to 50°C and the reaction is maintained for 2 hours to achieve the amination modification of silane.

[0032] 3. Add aminosilane: Add 3 grams of aminopropyltrimethoxysilane to the modified nano silica and continue the reaction at 60°C for 4 hours to enhance its hydrophilicity.

[0033] 4. Separation and purification: Unreacted aminosilanes were removed by centrifugation (9000 r / min, centrifugation time 15 minutes) to obtain modified nano-silica.

[0034] Example 2: 1. Material preparation: Mix 100g of nano silica with 6g of aminopropyltriethoxysilane (APTES) and stir until homogeneous to form a homogeneous mixture.

[0035] 2. Modification reaction: Under nitrogen protection, the homogeneous mixture is heated to 55°C and the reaction is maintained for 2 hours to achieve the amination modification of silane.

[0036] 3. Add aminosilane: Add 3 grams of aminopropyltrimethoxysilane to the modified nano silica and continue the reaction at 65°C for 4 hours.

[0037] 4. Separation and purification: Unreacted aminosilanes were removed by centrifugation (10,000 r / min, 10 minutes) to obtain modified nano-silica.

[0038] Example 3: 1. Material preparation: Mix 100g of nano silica with 7g of aminopropyltriethoxysilane (APTES) and stir until homogeneous to form a homogeneous mixture.

[0039] 2. Modification reaction: Under nitrogen protection, the homogeneous mixture is heated to 50°C and the reaction is maintained for 2 hours.

[0040] 3. Add aminosilane: Add 4 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane to the modified nano silica and continue the reaction at 60°C for 4 hours.

[0041] 4. Separation and purification: Unreacted aminosilanes were removed by centrifugation (8000 r / min, centrifugation time 20 minutes) to obtain modified nano-silica.

[0042] Example 4: 1. Material preparation: Mix 100g of nano silica with 5g of aminopropyltriethoxysilane (APTES) and stir until homogeneous to form a homogeneous mixture.

[0043] 2. Modification reaction: Under nitrogen protection, the homogeneous mixture is heated to 50°C and the reaction time is maintained for 3 hours.

[0044] 3. Add aminosilane: Add 3 grams of aminopropyltrimethoxysilane to the modified nano silica and continue the reaction at 60°C for 4 hours.

[0045] 4. Separation and purification: Unreacted aminosilanes were removed by centrifugation (12000 r / min, 15 minutes) to obtain modified nano-silica.

[0046] Comparative Example 1: 1. Material preparation: Mix 100g of nano silica with 5g of aminopropyltriethoxysilane (APTES) and 3g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, stir until homogeneous to form a homogeneous mixture, and react at 60℃ for 4 hours.

[0047] 2. Separation and purification: Unreacted aminosilanes were removed by centrifugation (12000 r / min, 15 minutes) to obtain modified nano-silica.

[0048] Comparative Example 2: 1. Material preparation: Mix 100g of nano silica with 5g of aminopropyltriethoxysilane (APTES) and stir until homogeneous to form a homogeneous mixture.

[0049] 2. Modification reaction: Under nitrogen protection, the homogeneous mixture is heated to 50°C and the reaction time is maintained for 3 hours.

[0050] 3. Separation and purification: Unreacted aminosilanes were removed by centrifugation (12000 r / min, 15 minutes) to obtain modified nano-silica.

[0051] Comparative Example 3: 1. Material preparation: Mix 100g of nano silica with 3g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and stir until homogeneous to form a homogeneous mixture.

[0052] 2. Modification reaction: Under nitrogen protection, the homogeneous mixture is heated to 50°C and the reaction time is maintained for 3 hours.

[0053] 3. Separation and purification: Unreacted aminosilanes were removed by centrifugation (12000 r / min, 15 minutes) to obtain modified nano-silica.

[0054] Experimental Example 1: The samples from Examples 1-4 and Comparative Example 3 were subjected to CO2 hydrate induction experiments. The specific procedure was as follows: the CO2 hydrate formation experiment was conducted under isochoric and isothermal conditions (250 cm⁻¹). 3The experiments were conducted at 0.5 °C. Hydrates formed in three solutions: aqueous solution (blank), Examples 1-4, and Comparative Examples 1-3. NaCl at a concentration of 0.1 mmol / L was used as the background salt solution. First, solutions of different systems were injected separately into pressure vessels to form hydrates; before immersing the vessels in a cooling bath maintained at 10 °C, air was removed from the autoclave by purging with gaseous CO2 through several compressions and decompressions. CO2 was then injected into the vessels to pressurize the system to 3.5 MPa. Before the hydrate experiments, CO2 was thoroughly dissolved in the solution using a magnetic stirrer at 500 rpm. The induction time for CO2 hydrate formation depended on the time span from the temperature decreasing to the equilibrium temperature (8.2 °C at 3.4 MPa) to the significant temperature increase at which rapid hydrate formation occurred. The results are as follows: Figure 1-8 As shown, the induction time of Examples 1-4 was lower than that of the blank example and Comparative Examples 1-3, proving that the silane-based amino-modified nano-silica carbon dioxide hydrate promoter of this invention has an excellent effect on promoting hydrate formation.

[0055] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a silane-based amino-modified nano-silica carbon dioxide hydrate promoter, comprising the following steps: (1) Mix nano-silica with aminopropyltriethoxysilane and stir to form a homogeneous mixture; (2) The homogeneous mixture is heated and reacted in an inert atmosphere to obtain modified nano-silica; (3) Add aminosilane to the modified nano silica, continue the reaction, and process after the reaction to obtain modified nano silica, which is a silane-based amino-modified nano silica carbon dioxide hydrate promoter.

2. The preparation method according to claim 1, characterized in that, In step (1), the mass ratio of the nano-silica to the aminopropyltriethoxysilane is 100:3~10.

3. The preparation method according to claim 1 or 2, characterized in that, In step (2), the inert atmosphere includes nitrogen; The temperature is then raised to 50℃~55℃; The reaction is carried out at a temperature of 50℃~55℃ for 1~4 hours.

4. The preparation method according to claim 1 or 2, characterized in that, In step (3), the aminosilane is selected from at least one of aminopropyltrimethoxysilane, aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane and aminopropylphenyldimethoxysilane.

5. The preparation method according to claim 1 or 2, characterized in that, In step (3), the reaction temperature is 60℃~65℃ and the time is 1~6 hours; The mass ratio of the aminosilane to the modified nano-silica is 1 to 5:

10.

6. The preparation method according to claim 1 or 2, characterized in that, Step (3) also includes centrifuging and washing the post-reaction system; The centrifugation speed is 8000~12000 r / min, and the time is 10~20 minutes.

7. The silane-based amino-modified nano-silica carbon dioxide hydrate promoter obtained by the preparation method according to any one of claims 1-6.

8. The application of the silane-based amino-modified nano-silica carbon dioxide hydrate promoter according to claim 7 in carbon dioxide capture and hydrate formation.

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