Carbon fiber felt for capturing carbon dioxide as well as preparation method and application of carbon fiber felt

Abstract

The invention discloses a carbon fiber felt for capturing carbon dioxide and a preparation method thereof.The preparation method comprises the following steps that S1, the carbon fiber felt is soaked in a zinc salt solution, zinc salt is evenly distributed in pores of the carbon fiber felt, and a precursor carbon fiber felt material is obtained; s2, adding the precursor carbon fiber felt material and 1, 2, 4-triazole into an alcohol solvent, and reacting for 6 to 72 hours under a heating condition, so as to obtain an in-situ growth CALF-20 / carbon fiber felt material; and S3, washing and drying the in-situ grown CALF-20 / carbon fiber felt material to obtain the carbon fiber felt for capturing carbon dioxide. The CALF-20 is synthesized in situ in the porous structure of the carbon fiber felt, the CALF-20 can be used for carrying out carbon capture on flue gas, the raw materials are cheap, the preparation method is simple, and large-scale production is easy to realize.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide capture, and in particular to a carbon fiber felt for capturing carbon dioxide, and a preparation method and application thereof. Background Art

[0002] Carbon capture, utilization and storage (CCUS) refers to a technology that captures, purifies, recycles or stores carbon dioxide emitted during the production process. Carbon capture refers to the collection and storage of carbon dioxide produced by emission sources such as large power plants, steel mills, and cement plants in various ways to prevent it from being directly emitted into the atmosphere; this technology has the synergistic effect of achieving large-scale greenhouse gas emission reduction and low-carbon utilization of fossil energy, and is one of the important technical options for the future global response to climate change.

[0003] Carbon capture from flue gas is one of the important scenarios of CCUS. It consumes a lot of energy for separation and has a high capture cost. The main component of flue gas is nitrogen (N2), while carbon dioxide (CO2) accounts for only about 15%, and it also contains water and acidic gases, which greatly increases the difficulty of carbon capture. Traditional organic amine solution captures CO2 by combining chemical adsorption and physical adsorption. Its regeneration process consumes a lot of energy, and the organic amine will also undergo decomposition reactions, thereby increasing the capture cost.

[0004] Solid adsorption material is a more advanced carbon capture material. It not only has stable performance and structure, but also has higher selectivity and adsorption capacity for CO2. MOFs is a new type of porous solid adsorption material, assembled from metal ions and organic ligands, with extremely high specific surface area, abundant active sites, adjustable pore structure, good stability and easy modification and functionalization. Recent studies have found that CALF-20 can effectively solve the problems of high energy consumption and high capture cost of traditional organic amine solution to capture CO2. CALF-20 can capture carbon in actual flue gas, and the raw materials for preparation are very cheap. However, as a MOFs powder material, single CALF-20 is difficult to recycle, which limits its industrial application, and the preparation and application process is prone to pollution.

[0005] Carbon fiber felt is a widely used adsorption and purification material with a highly developed microporous structure, large adsorption capacity, fast desorption speed and good purification effect. If MOFs particles are converted into self-supporting, flexible carbon fiber felt, it can not only solve the problems faced by MOFs materials in practical applications, maintain the intrinsic properties, but also improve the comprehensive performance of the material through synergy with carbon fiber felt. Therefore, the development of a self-supporting CALF-20 / carbon fiber felt material is of great significance for the capture of carbon dioxide from flue gas. Summary of the invention

[0006] In view of the defects existing in the prior art, the purpose of the present invention is to provide a carbon fiber felt for capturing carbon dioxide and a preparation method and application thereof. CALF-20 is synthesized in situ in the porous structure of the carbon fiber felt, which can be used for carbon capture of flue gas. In addition, the raw materials are cheap, the preparation method is simple, and large-scale production is easy to achieve.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A first aspect of the present invention provides a method for preparing a carbon fiber felt for capturing carbon dioxide, comprising the following steps:

[0009] S1, soaking the carbon fiber felt in a zinc salt solution to make the zinc salt evenly distributed in the porous structure of the carbon fiber felt to obtain a precursor carbon fiber felt material;

[0010] S2, adding the precursor carbon fiber felt material and 1,2,4-triazole to an alcohol solvent, and reacting for 6 to 72 hours under heating conditions to obtain an in-situ grown CALF-20 / carbon fiber felt material;

[0011] S3, washing and drying the in-situ grown CALF-20 / carbon fiber felt material to obtain a carbon fiber felt for capturing carbon dioxide.

[0012] Preferably, in step S1:

[0013] The carbon fiber felt is one or more of nano-polyacrylonitrile-based carbon fiber felt, micron-polyacrylonitrile-based carbon fiber felt, general-grade asphalt-based carbon fiber felt, mesophase asphalt-based carbon fiber felt, and viscose-based carbon fiber felt; and / or

[0014] The zinc salt is selected from one or more of zinc oxalate, zinc nitrate, zinc sulfate, zinc chloride, zinc carbonate, zinc phosphate, and zinc fluoroborate.

[0015] The solvent used for the zinc salt solution is selected from one or more of water, methanol, ethanol, acetone, sulfuric acid, and ammonia water.

[0016] Preferably, in step S1:

[0017] The weight ratio of the carbon fiber felt to the zinc salt is 1:0.1 to 1:1; the concentration of the zinc salt solution is 100 to 500 g / L; and / or

[0018] The soaking time is 0.1 to 3 hours.

[0019] Preferably, in step S1, the soaking time is 0.5 to 2 hours.

[0020] Preferably, in step S2:

[0021] The alcohol solvent is one or more of methanol, ethanol, isopropanol and butanol; and / or

[0022] The weight ratio of the precursor carbon fiber felt material to 1,2,4-triazole is 1:0.5 to 1:5; the weight of the alcohol solvent is 5 to 30 parts, with the weight of the precursor carbon fiber felt material being 1 part by weight.

[0023] Preferably, the weight ratio of the precursor carbon fiber felt material to 1,2,4-triazole is 1:1 to 1:3; and the weight proportion of the alcohol solvent is 8 to 20 parts.

[0024] Preferably, during the heating process of step S2, the heating temperature is 120-260° C. and the reaction pressure is 0.1-10 MPa.

[0025] Preferably, during the heating process, the heating temperature is 150-220° C., the reaction pressure is 1-5 MPa, and the reaction time is 24-48 h.

[0026] The second aspect of the present invention provides a carbon fiber felt for capturing carbon dioxide, which is prepared by the method for preparing the carbon fiber felt for capturing carbon dioxide as described in the first aspect of the present invention, wherein the specific surface area of ​​the carbon fiber felt for capturing carbon dioxide is 300 to 500 m 2 / g, and the porosity is above 90%.

[0027] The third aspect of the present invention provides an application of a carbon fiber felt for capturing carbon dioxide in capturing carbon dioxide in flue gas, wherein the carbon fiber felt for capturing carbon dioxide is prepared by the preparation method of the carbon fiber felt for capturing carbon dioxide as described in the first aspect of the present invention.

[0028] The beneficial effects of the present invention are:

[0029] 1. The present invention grows the traditional CALF-20 powder in situ in the porous structure of the self-supporting composite carbon fiber felt with certain mechanical properties, which can not only maintain the intrinsic properties of the material, but also improve the comprehensive performance of the material through the synergistic effect with the carbon fiber felt;

[0030] 2. The carbon fiber felt for capturing carbon dioxide and the preparation method thereof of the present invention use CALF-20 powder in the form of carbon fiber felt, and there is no dust pollution during the preparation and application process, and it can be recycled and easily realized industrial application;

[0031] 3. The carbon fiber felt for capturing carbon dioxide prepared by the present invention can be used to capture carbon from flue gas and reduce carbon emissions. In addition, the raw materials are cheap, the preparation method is simple, and large-scale production can be easily achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0033] Figure 1 A schematic diagram of the process of preparing a carbon fiber felt for capturing carbon dioxide according to the present invention;

[0034] Figure 2 Schematic diagram of the microstructure of the carbon fiber felt for capturing carbon dioxide prepared in the present invention, wherein (a) is a photograph of the carbon fiber felt for capturing carbon dioxide, (b) is a microscopic schematic diagram of point A in (a); and (c) is a schematic diagram of the structure in which CALF-20 is embedded in the interior or surface of the carbon fiber felt. DETAILED DESCRIPTION

[0035] The present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form.

[0036] Combination Figure 1 As shown, the present invention provides a method for preparing a carbon fiber felt for capturing carbon dioxide, comprising the following steps:

[0037] S1, soaking the carbon fiber felt in a zinc salt solution to make the zinc salt evenly distributed in the porous structure of the carbon fiber felt to obtain a precursor carbon fiber felt material;

[0038] Specifically, the carbon fiber felt is soaked in a zinc salt solution for 0.1 to 3 hours to make the zinc salt evenly distributed in the porous structure of the carbon fiber felt to obtain a precursor carbon fiber felt material. The carbon fiber felt is one or more of nano-polyacrylonitrile-based carbon fiber felt, micron-polyacrylonitrile-based carbon fiber felt, general-grade asphalt-based carbon fiber felt, intermediate phase asphalt-based carbon fiber felt, and viscose-based carbon fiber felt. The thickness of the carbon fiber felt is 2 to 10 cm, and the bulk density is 0.05 to 0.15 g / cm 3 The zinc salt is selected from one or more of zinc oxalate, zinc nitrate, zinc sulfate, zinc chloride, zinc carbonate, zinc phosphate, and zinc fluoroborate; the solvent used for the zinc salt solution is selected from one or more of water, methanol, ethanol, acetone, sulfuric acid, and ammonia water. The weight ratio of the above-mentioned carbon fiber felt to the zinc salt is 1:0.1 to 1:1; the concentration of the zinc salt solution is 100 to 500 g / L. The immersion time is 0.5 to 2 hours.

[0039] S2, adding the precursor carbon fiber felt material and 1,2,4-triazole into an alcohol solvent, and reacting for 6 to 72 hours under heating conditions to obtain an in-situ grown CALF-20 / carbon fiber felt material;

[0040] Specifically, the precursor carbon fiber felt material and 1,2,4-triazole are prepared in a weight ratio of 1:0.5 to 1:5, and added to an alcohol solvent with a weight of 5 to 30 parts, and reacted for 6 to 72 hours at a heating temperature of 120 to 260°C and a reaction pressure of 0.1 to 10 MPa to obtain an in-situ grown CALF-20 / carbon fiber felt material. Among them, when calculating the weight of the alcohol solvent, the weight of the precursor carbon fiber felt material is 1 part by weight. In a specific embodiment, the alcohol solvent is one or more of methanol, ethanol, isopropanol, and butanol. The weight ratio of the precursor carbon fiber felt material to 1,2,4-triazole is 1:1 to 1:3; the weight of the alcohol solvent is 8 to 20 parts. The heating temperature is 150 to 220°C, the reaction pressure is 1 to 5 MPa, and the reaction time is 24 to 48 hours.

[0041] S3, washing and drying the in-situ grown CALF-20 / carbon fiber felt material multiple times to obtain a carbon fiber felt for capturing carbon dioxide, wherein the washing solvent may be methanol or the like; the specific surface area of ​​the carbon fiber felt for capturing carbon dioxide is 300 to 500 m 2 / g, and the porosity is above 90%.

[0042] Combination Figure 2 As shown, on the carbon fiber felt for capturing carbon dioxide prepared by the above method, CALF-20 is embedded in the interior or surface of the carbon fiber felt (see Figure 2 (b) and (c) in the figure), so it has certain mechanical properties, which can not only maintain the intrinsic characteristics of the carbon fiber felt material, but also enhance the carbon capture under the joint action of the two due to the adsorption capacity of the carbon fiber felt.

[0043] When the carbon fiber felt prepared above for capturing carbon dioxide is used to capture carbon dioxide in flue gas, the removal rate of carbon dioxide in flue gas reaches more than 91%, and the purity of the captured carbon dioxide can reach more than 91%.

[0044] The carbon fiber felt for capturing carbon dioxide and its preparation method and application of the present invention are further introduced below with reference to specific examples.

[0045] Example 1

[0046] The method for preparing the carbon fiber felt for capturing carbon dioxide in this embodiment adopts the following steps:

[0047] (1) The thickness is 4.5 cm and the bulk density is 0.09 g / cm 3 The micron polyacrylonitrile-based carbon fiber felt is immersed in a 30wt% sulfuric acid solution of zinc oxalate for 1 hour to make the zinc oxalate evenly distributed in the porous structure of the carbon felt, thereby obtaining a precursor carbon fiber felt material.

[0048] (2) Weigh 50 g of the precursor carbon fiber felt material obtained in step (1) and 100 g of 1,2,4-triazole, add them to 900 g of methanol, and react at a temperature of 180° C. and a pressure of 1.5 MPa for 40 hours to obtain an in-situ grown CALF-20 / carbon fiber felt material.

[0049] (3) The carbon fiber felt material obtained in step (2) is washed with methanol for multiple times and dried to obtain a carbon fiber felt material for capturing carbon dioxide, the specific surface area of ​​which is 446.2 m 2 / g, and the porosity is 92.7%.

[0050] The carbon fiber felt material prepared above was used for flue gas (gas volume 3Nm 3 / h, carbon dioxide content 15%), the carbon dioxide removal rate is 98.5%, and the purity of the captured carbon dioxide is 98.1%.

[0051] Example 2

[0052] The method for preparing the carbon fiber felt for capturing carbon dioxide in this embodiment adopts the following steps:

[0053] (1) The thickness is 3.5 cm and the bulk density is 0.06 g / cm 3 The general-grade asphalt-based carbon fiber felt is immersed in a sulfuric acid solution of 20 wt% zinc oxalate for 1.2 hours to make the zinc oxalate evenly distributed in the porous structure of the carbon felt, thereby obtaining a precursor carbon fiber felt material.

[0054] (2) Weigh 50 g of the precursor carbon fiber felt material and 80 g of 1,2,4-triazole obtained in step (1), add them to 600 g of ethanol, and react at a temperature of 160° C. and a pressure of 2 MPa for 36 hours to obtain an in-situ grown CALF-20 / carbon fiber felt material.

[0055] (3) The carbon fiber felt material obtained in step (2) is washed with methanol for multiple times and dried to obtain a carbon fiber felt material for capturing carbon dioxide, the specific surface area of ​​which is 388.7 m 2 / g, and the porosity is 91.8%.

[0056] The carbon fiber felt material prepared above was used for flue gas (gas volume 3Nm 3 / h, carbon dioxide content 15%), the carbon dioxide removal rate is 98.3%, and the purity of the captured carbon dioxide is 92.2%.

[0057] Example 3

[0058] The method for preparing the carbon fiber felt for capturing carbon dioxide in this embodiment adopts the following steps:

[0059] (1) The thickness is 7 cm and the bulk density is 0.11 g / cm 3 The viscose-based carbon fiber felt was immersed in a sulfuric acid / water mixed solution (50:50) of 10wt% zinc oxalate and 10wt% zinc nitrate for 1.5 hours to make the zinc oxalate and zinc nitrate evenly distributed in the porous structure of the carbon felt, thereby obtaining a precursor carbon fiber felt material.

[0060] (2) Weigh 50 g of the precursor carbon fiber felt material and 60 g of 1,2,4-triazole obtained in step (1), add them to 700 g of methanol, and react at a temperature of 170° C. and a pressure of 1.7 MPa for 45 hours to obtain an in-situ grown CALF-20 / carbon fiber felt material.

[0061] (3) The carbon fiber felt material obtained in step (2) is washed with methanol for multiple times and dried to obtain a carbon fiber felt material for capturing carbon dioxide, the specific surface area of ​​which is 310.5 m 2 / g, and the porosity is 90.3%.

[0062] The carbon fiber felt material prepared above was used for flue gas (gas volume 3Nm 3 / h, carbon dioxide content 15%), the carbon dioxide removal rate is 91.8%, and the purity of the captured carbon dioxide is 94.5%.

[0063] Example 4

[0064] The method for preparing the carbon fiber felt for capturing carbon dioxide in this embodiment adopts the following steps:

[0065] (1) The thickness is 6.5 cm and the bulk density is 0.12 g / cm 3 The nano / micron hybrid polyacrylonitrile-based carbon fiber felt was immersed in a sulfuric acid / water (60:40) mixed solution of 15wt% zinc oxalate and 10wt% zinc sulfate for 1 hour to make the zinc oxalate and zinc sulfate evenly distributed in the porous structure of the carbon felt, thereby obtaining a precursor carbon fiber felt material.

[0066] (2) Weigh 50 g of the precursor carbon fiber felt material obtained in step (1) and 125 g of 1,2,4-triazole, add them to 900 g of butanol, and react at a temperature of 170° C. and a pressure of 1.7 MPa for 45 hours to obtain an in-situ grown CALF-20 / carbon fiber felt material.

[0067] (3) The carbon fiber felt material obtained in step (2) is washed with methanol for multiple times and dried to obtain a carbon fiber felt material for capturing carbon dioxide, the specific surface area of ​​which is 476.4 m 2 / g, and the porosity is 92.4%.

[0068] The carbon fiber felt material prepared above was used for flue gas (gas volume 3Nm3 / h, carbon dioxide content 15%), the carbon dioxide removal rate is 98.6%, and the purity of the captured carbon dioxide is 99.1%.

[0069] Example 5

[0070] The method for preparing the carbon fiber felt for capturing carbon dioxide in this embodiment adopts the following steps:

[0071] (1) The thickness is 5 cm and the bulk density is 0.08 g / cm 3 The micron polyacrylonitrile / mesophase pitch-based hybrid carbon fiber felt was immersed in a 30wt% zinc oxalate sulfuric acid solution for 1 hour to make the zinc oxalate evenly distributed in the porous structure of the carbon felt, thereby obtaining a precursor carbon fiber felt material.

[0072] (2) Weigh 50 g of the precursor carbon fiber felt material obtained in step (1) and 100 g of 1,2,4-triazole, add them to 500 g of isopropanol, and react at a temperature of 200° C. and a pressure of 3 MPa for 25 hours to obtain an in-situ grown CALF-20 / carbon fiber felt material.

[0073] (4) The carbon fiber felt material obtained in step (3) is washed with methanol for multiple times and dried to obtain a carbon fiber felt material for capturing carbon dioxide, the specific surface area of ​​which is 349.2 m 2 / g, and the porosity is 90.9%.

[0074] The carbon fiber felt material prepared above was used for flue gas (gas volume 3Nm 3 / h, carbon dioxide content 15%), the carbon dioxide removal rate is 94.1%, and the purity of the captured carbon dioxide is 91.3%.

[0075] In summary, the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing carbon fiber felt for capturing carbon dioxide, characterized in that: The following steps are involved: S1, soaking the carbon fiber felt in a zinc salt solution to make the zinc salt evenly distributed in the porous structure of the carbon fiber felt to obtain a precursor carbon fiber felt material; S2, adding the precursor carbon fiber felt material and 1,2,4-triazole to an alcohol solvent, and reacting for 6 to 72 hours under heating conditions to obtain an in-situ grown CALF-20 / carbon fiber felt material; S3, washing and drying the in-situ grown CALF-20 / carbon fiber felt material to obtain a carbon fiber felt for capturing carbon dioxide.

2. The method for preparing carbon fiber felt for capturing carbon dioxide according to claim 1, characterized in that: In step S1: The carbon fiber felt is one or more of nano-polyacrylonitrile-based carbon fiber felt, micron-polyacrylonitrile-based carbon fiber felt, general-grade asphalt-based carbon fiber felt, mesophase asphalt-based carbon fiber felt, and viscose-based carbon fiber felt; and / or The zinc salt is selected from one or more of zinc oxalate, zinc nitrate, zinc sulfate, zinc chloride, zinc carbonate, zinc phosphate, and zinc fluoroborate. The solvent used for the zinc salt solution is selected from one or more of water, methanol, ethanol, acetone, sulfuric acid, and ammonia water.

3. The method for preparing carbon fiber felt for capturing carbon dioxide according to claim 1, characterized in that: In step S1: The weight ratio of the carbon fiber felt to the zinc salt is 1:0.1 to 1:1; the concentration of the zinc salt solution is 100 to 500 g / L; and / or The soaking time is 0.1 to 3 hours.

4. The method for preparing carbon fiber felt for capturing carbon dioxide according to claim 3, characterized in that: In the step S1, the soaking time is 0.5 to 2 hours.

5. The method for preparing carbon fiber felt for capturing carbon dioxide according to claim 1, characterized in that: In step S2: The alcohol solvent is one or more of methanol, ethanol, isopropanol and butanol; and / or The weight ratio of the precursor carbon fiber felt material to 1,2,4-triazole is 1:0.5 to 1:5; the weight of the alcohol solvent is 5 to 30 parts, with the weight of the precursor carbon fiber felt material being 1 part by weight.

6. The method for preparing carbon fiber felt for capturing carbon dioxide according to claim 5, characterized in that: The weight ratio of the precursor carbon fiber felt material to 1,2,4-triazole is 1:1 to 1:3; the weight proportion of the alcohol solvent is 8 to 20 parts.

7. The method for preparing carbon fiber felt for capturing carbon dioxide according to claim 1, characterized in that: During the heating process of step S2, the heating temperature is 120-260° C. and the reaction pressure is 0.1-10 MPa.

8. The method for preparing carbon fiber felt for capturing carbon dioxide according to claim 7, characterized in that: During the heating process, the heating temperature is 150-220° C., the reaction pressure is 1-5 MPa, and the reaction time is 24-48 hours.

9. A carbon fiber felt for capturing carbon dioxide, characterized in that: The carbon fiber felt for capturing carbon dioxide is prepared by the method for preparing the carbon fiber felt for capturing carbon dioxide according to any one of claims 1 to 8, wherein the specific surface area of ​​the carbon fiber felt for capturing carbon dioxide is 300 to 500 m 2 / g, and the porosity is above 90%.

10. An application of a carbon fiber felt for capturing carbon dioxide in flue gas, characterized in that: The carbon fiber felt for capturing carbon dioxide is prepared by the method for preparing the carbon fiber felt for capturing carbon dioxide as described in any one of claims 1 to 8.

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